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Sample records for active x-ray telescopes

  1. Toward Active X-ray Telescopes II

    NASA Technical Reports Server (NTRS)

    O'Dell, Stephen L.; Aldroft, Thomas L.; Atkins, Carolyn; Button, Timothy W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peter; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Johnson-Wilke, Raegan L.; Kolodziejczak, Jeffery J.; Lillie, Charles F.; Michette, Alan G.; Ramsey, Brian D.; Reid, Paul B.; Sanmartin, Daniel Rodriguez; Saha, Timo T.; Schwartz, Daniel A.; Trolier-McKinstry, Susan E.; Ulmer, Melville P.; Wilke, Rudeger H. T.; Willingale, Richard; Zhang, William W.

    2012-01-01

    In the half century since the initial discovery of an astronomical (non-solar) x-ray source, the sensitivity for detection of cosmic x-ray sources has improved by ten orders of magnitude. Largely responsible for this dramatic progress has been the refinement of the (grazing-incidence) focusing x-ray telescope. The future of x-ray astronomy relies upon the development of x-ray telescopes with larger aperture areas (greater than 1 m2) and finer angular resolution (less than 1.). Combined with the special requirements of grazing-incidence optics, the mass and envelope constraints of space-borne telescopes render such advances technologically challenging.requiring precision fabrication, alignment, and assembly of large areas (greater than 100 m2) of lightweight (approximately 1 kg m2 areal density) mirrors. Achieving precise and stable alignment and figure control may entail active (in-space adjustable) x-ray optics. This paper discusses relevant programmatic and technological issues and summarizes progress toward active x-ray telescopes.

  2. Toward active x-ray telescopes

    NASA Astrophysics Data System (ADS)

    O'Dell, Stephen L.; Atkins, Carolyn; Button, Timothy W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peter; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffery J.; Michette, Alan G.; Ramsey, Brian D.; Reid, Paul B.; Rodriguez Sanmartin, Daniel; Saha, Timo T.; Schwartz, Daniel A.; Trolier-McKinstry, Susan; Wilke, Rudeger H. T.; Willingale, Richard; Zhang, William W.

    2011-09-01

    Future x-ray observatories will require high-resolution (< 1") optics with very-large-aperture (> 25 m2) areas. Even with the next generation of heavy-lift launch vehicles, launch-mass constraints and aperture-area requirements will limit the areal density of the grazing-incidence mirrors to about 1 kg/m2 or less. Achieving sub-arcsecond x-ray imaging with such lightweight mirrors will require excellent mirror surfaces, precise and stable alignment, and exceptional stiffness or deformation compensation. Attaining and maintaining alignment and figure control will likely involve active (in-space adjustable) x-ray optics. In contrast with infrared and visible astronomy, active optics for x-ray astronomy is in its infancy. In the middle of the past decade, two efforts began to advance technologies for adaptive x-ray telescopes: The Smart X-ray Optics (SXO) Basic Technology project in the United Kingdom (UK) and the Generation-X (Gen-X) concept studies in the United States (US). This paper discusses relevant technological issues and summarizes progress toward active x-ray telescopes.

  3. Activities in the X-Ray Corona as seen by Hinode X-Ray Telescope

    NASA Astrophysics Data System (ADS)

    Sakao, Taro

    We present observations on the solar corona with the X-Ray Telescope (XRT) aboard Hinode. XRT is a grazing-incidence imager with a Walter Type-I-like mirror of 34 cm diameter, with a back-illuminated CCD device located at its focus position. In addition to its imaging capability for the X-ray corona with the highest angular resolution (consistent with 1 arcsec CCD pixel size) as a solar X-ray telescope, enhanced sensitivity of the CCD towards longer X-ray wavelengths (particularly longer than 50 angstroms) enables XRT to image, and perform temperature diagnostics on, coronal plasmas in a wide temperature range (1-10 MK). This adds a notable advantage to XRT that it can observe most, if not all, active phenomena in the corona throughout their entire thermal evolution. XRT has so far revealed various new aspects of coronal activities. These include (1) plasma flows in the corona, (2) frequent X-ray jets in the polar regions, (3) eruptive events even with small or moderate X-ray activities, (4) fine structure and evolution of flaring loops, (5) detailed observations on transient brightenings (microflares) in quiet as well as active regions. Some highlights of Hinode XRT observations, centered on those on plasma flows, will be presented and discussed.

  4. Active optics and x-ray telescope mirrors

    NASA Astrophysics Data System (ADS)

    Lemaitre, Gérard R.

    2008-07-01

    For more than 40 years in Marseille Provence observatories active optics concepts have found many fruitful developments in uv, visible and ir telescope optics. For these wavelength ranges, active optics methods are now widely extended by current use of variable curvature mirrors, in situ aspherization processes, stress figuring apsherization processes, replications of stressed diffraction gratings, and in situ control of large telescope optics. X-ray telescope mirrors will also benefit soon from the enhanced performances of active optics. For instance, the 0.5-1 arcsec spatial resolution of Chandra will be followed up by increased resolution space telescopes which will require the effective construction of more strictly aplanatic grazing-incidence two-mirror systems. In view to achieve a high-resolution imaging with two-mirror grazing-incidence telescope, say, 0.1 arcsec, this article briefly reviews the alternative optical concepts. Next, active optics analysis is investigated with the elasticity theory of shells for the active aspherization and in situ control of monolithic and segmented telescope mirrors for x-ray astronomy. An elasticity theory of weakly conical shells is developed for a first approach which uses a monotonic extension (or retraction) of the shell.

  5. The x-ray/EUV telescope for the Solar-C mission: science and development activities

    NASA Astrophysics Data System (ADS)

    Sakao, Taro; Narukage, Noriyuki; Imada, Shinsuke; Suematsu, Yoshinori; Shimojo, Masumi; Tsuneta, Saku; DeLuca, Edward E.; Watanabe, Kyoko; Ishikawa, Shin-nosuke

    2012-09-01

    We report science and development activities of the X-ray/EUV telescope for the Japanese Solar-C mission whose projected launch around 2019. The telescope consists of a package of (a) a normal-incidence (NI) EUV telescope and (b) a grazing-incidence (GI) soft X-ray telescope. The NI telescope chiefly provides images of low corona (whose temperature 1 MK or even lower) with ultra-high angular resolution (0.2-0.3"/pixel) in 3 wavelength bands (304, 171, and 94 angstroms). On the other hand, the GI telescope provides images of the corona with a wide temperature coverage (1 MK to beyond 10 MK) with the highest-ever angular resolution (~0.5"/pixel) as a soft X-ray coronal imager. The set of NI and GI telescopes should provide crucial information for establishing magnetic and gas-dynamic connection between the corona and the lower atmosphere of the Sun which is essential for understanding heating of, and plasma activities in, the corona. Moreover, we attempt to implement photon-counting capability for the GI telescope with which imaging-spectroscopy of the X-ray corona will be performed for the first time, in the energy range from ~0.5 keV up to 10 keV. The imaging-spectroscopic observations will provide totally-new information on mechanism(s) for the generation of hot coronal plasmas (heated beyond a few MK), those for magnetic reconnection, and even generation of supra-thermal electrons associated with flares. An overview of instrument outline and science for the X-ray photoncounting telescope are presented, together with ongoing development activities in Japan towards soft X-ray photoncounting observations, focusing on high-speed X-ray CMOS detector and sub-arcsecond-resolution GI mirror.

  6. Focusing X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    O'Dell, Stephen; Brissenden, Roger; Davis, William; Elsner, Ronald; Elvis, Martin; Freeman, Mark; Gaetz, Terrance; Gorenstein, Paul; Gubarev, Mikhall; Jerlus, Diab; Juda, Michael; Kolodziejczak, Jeffrey; Murray, Stephen; Petre, Robert; Podgorski, William; Ramsey, Brian; Reid, Paul; Saha, Timo; Wolk, Scott; Troller-McKinstry, Susan; Weisskopf, Martin; Wilke, Rudeger; Zhang, William

    2010-01-01

    During the half-century history of x-ray astronomy, focusing x-ray telescopes, through increased effective area and finer angular resolution, have improved sensitivity by 8 orders of magnitude. Here, we review previous and current x-ray-telescope missions. Next, we describe the planned next-generation x-ray-astronomy facility, the International X-ray Observatory (IXO). We conclude with an overview of a concept for the next next-generation facility, Generation X. Its scientific objectives will require very large areas (about 10,000 sq m) of highly-nested, lightweight grazing-incidence mirrors, with exceptional (about 0.1-arcsec) resolution. Achieving this angular resolution with lightweight mirrors will likely require on-orbit adjustment of alignment and figure.

  7. Normal incidence X-ray telescope power spectra of X-ray emission from solar active regions. I - Observations. II - Theory

    NASA Technical Reports Server (NTRS)

    Gomez, Daniel O.; Martens, Petrus C. H.; Golub, Leon

    1993-01-01

    Fourier analysis is applied to very high resolution image of coronal active regions obtained by the Normal Incidence X-Ray Telescope is used to find a broad isotropic power-law spectrum of the spatial distribution of soft X-ray intensities. Magnetic structures of all sizes are present down to the resolution limit of the instrument. Power spectra for the X-ray intensities of a sample of topologically different active regions are found which fall off with increasing wavenumber as 1/k-cubed. A model is presented that relates the basic features of coronal magnetic fluctuations to the subphotospheric hydrodynamic turbulence that generates them. The model is used to find a theoretical power spectrum for the X-ray intensity which falls off with increasing wavenumber as 1/k-cubed. The implications of a turbulent regime in active regions are discussed.

  8. Diffractive X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    Skinner, Gerald K.

    2010-01-01

    Diffractive X-ray telescopes, using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution many orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the super-massive black holes in the center of active galaxies. What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

  9. X-ray photographs of a solar active region with a multilayer telescope at normal incidence

    NASA Technical Reports Server (NTRS)

    Underwood, J. H.; Bruner, M. E.; Haisch, B. M.; Brown, W. A.; Acton, L. W.

    1987-01-01

    An astronomical photograph was obtained with a multilayer X-ray telescope. A 4-cm tungsten-carbon multilayer mirror was flown as part of an experimental solar rocket payload, and successful images were taken of the sun at normal incidence at a wavelength of 44 A. Coronal Si XII emission from an active region was recorded on film; as expected, the structure is very similar to that observed at O VIII wavelengths by the Solar Maximum Mission flat-crystal spectrometer at the same time. The small, simple optical system used in this experiment appears to have achieved a resolution of 5 to 10 arcsec.

  10. Modeling active region transient brightenings observed with X-ray telescope as multi-stranded loops

    SciTech Connect

    Kobelski, Adam R.; McKenzie, David E.; Donachie, Martin

    2014-05-10

    Strong evidence exists that coronal loops as observed in extreme ultraviolet and soft X-rays may not be monolithic isotropic structures, but can often be more accurately modeled as bundles of independent strands. Modeling the observed active region transient brightenings (ARTBs) within this framework allows for the exploration of the energetic ramifications and characteristics of these stratified structures. Here we present a simple method of detecting and modeling ARTBs observed with the Hinode X-Ray Telescope (XRT) as groups of zero-dimensional strands, which allows us to probe parameter space to better understand the spatial and temporal dependence of strand heating in impulsively heated loops. This partially automated method can be used to analyze a large number of observations to gain a statistical insight into the parameters of coronal structures, including the number of heating events required in a given model to fit the observations. In this article, we present the methodology and demonstrate its use in detecting and modeling ARTBs in a sample data set from Hinode/XRT. These initial results show that, in general, multiple heating events are necessary to reproduce observed ARTBs, but the spatial dependence of these heating events cannot yet be established.

  11. Spectral slicing X-ray telescope

    NASA Technical Reports Server (NTRS)

    Hoover, R. B.; Shealy, D.; Chao, S.-H.

    1986-01-01

    Layered synthetic microstructure (LSM) X-ray optics is investigated as a system for coupling a conventional glancing incidence X-ray mirror to a high sensitivity X-ray detector. It is shown that, by the use of figured LSM optics, it is possible to magnify the X-ray image produced by the primary mirrors so as to maintain their high inherent spatial resolution. The results of theoretical and design analyses of several spectral slicing X-ray telescope systems that utilize LSM mirrors of hyperboloidal, spherical, ellipsoidal, and constant optical path aspheric configurations are presented. It is shown that the spherical LSM optics are the preferred configuration, yielding subarcsecond performance over the entire field. The Stanford/Marshall Space Flight Center Rocket X-ray Telescope, which will utilize normal incidence LSM optics to couple a Wolter-Schwarzschild primary mirror to high resolution detectors for solar X-ray/EUV studies, is discussed. Design diagrams are included.

  12. Hot Plasma from Solar Active-Region Cores: Constraints from the Hinode X-Ray Telescope

    NASA Astrophysics Data System (ADS)

    Schmelz, J. T.; Christian, G. M.; Matheny, P. O.

    2016-12-01

    Mechanisms invoked to heat the solar corona to millions of degrees kelvin involve either magnetic waves or magnetic reconnections. Turbulence in the convection zone produces MHD waves, which travel upward and dissipate. Photospheric motions continuously build up magnetic energy, which is released through magnetic reconnection. In this paper, we concentrate on hot non-flaring plasma with temperatures of 5 MK < T < 10 MK because it is one of the few observables for which wave and reconnection models make different predictions. Wave models predict no (or little) hot plasma, whereas reconnection models predict it, although in amounts that are challenging to detect with current instrumentation. We used data from the X-ray Telescope (XRT) and the Atmospheric Imaging Assembly (AIA). We requested a special XRT observing sequence, which cycled through the thickest XRT filter several times per hour so we could average these images and improve the signal-to-noise. We did differential emission measure (DEM) analysis using the time-averaged thick-filter data as well as all available channels from both the XRT and AIA for regions observed on 2014 December 11. Whereas our earlier work was only able to determine that plasma with a temperature greater than 5 MK was present, we are now able to find a well-constrained DEM distribution. We have therefore added a strong observational constraint that must be explained by any viable coronal heating model. Comparing state-of-the-art wave and reconnection model predictions, we can conclude that reconnection is heating the hot plasma in these active regions.

  13. Variable magnification glancing incidence x ray telescope

    NASA Technical Reports Server (NTRS)

    Hoover, Richard (Inventor)

    1990-01-01

    A multispectral glancing incidence x ray telescope is disclosed, which capable of broadband, high resolution imaging of solar and stellar x ray and extreme ultraviolet radiation sources includes a primary optical system which focuses the incoming radiation to a primary focus. Two or more ellipsoidal mirrors are positioned behind the primary focus at an inclination to the optical axis, each mirror having a concave surface coated with a multilayer synthetic microstructure coating to reflect a desired wavelength. The ellipsoidal mirrors are segments of respective ellipsoids having a common first focus coincident with the primary focus. A detector such as an x ray sensitive photographic film is positioned at the second focus of each of the ellipsoids so that each of the ellipsoidal mirrors may reflect the image at the first focus to the detector. In one embodiment the mirrors are inclined at different angles and has its respective second focus at a different location, separate detectors being located at the respective second focus. The mirrors are arranged so that the magnification and field of view differ, and a solenoid activated arm may withdraw at least one mirror from the beam to select the mirror upon which the beam is to impinge so that selected magnifications and fields of view may be detected.

  14. Toward Adaptive X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    O'Dell, Stephen L.; Atkins, Carolyn; Button, Tim W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peer; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffrey J.; Michette, Alan G.; Ramsey, Brian D.; Reid, Paul B.; Rodriguez Sanmartin, Daniel; Saha, Timo T.; Schwartz, Daniel A.; Trolier-McKinstry, Susan; Wilke, Rudeger H. T.; Willingale, Richard; Zhang, William W.

    2011-01-01

    Future x-ray observatories will require high-resolution (less than 1 inch) optics with very-large-aperture (greater than 25 square meter) areas. Even with the next generation of heavy-lift launch vehicles, launch-mass constraints and aperture-area requirements will limit the surface areal density of the grazing-incidence mirrors to about 1 kilogram per square meter or less. Achieving sub-arcsecond x-ray imaging with such lightweight mirrors will require excellent mirror surfaces, precise and stable alignment, and exceptional stiffness or deformation compensation. Attaining and maintaining alignment and figure control will likely involve adaptive (in-space adjustable) x-ray optics. In contrast with infrared and visible astronomy, adaptive optics for x-ray astronomy is in its infancy. In the middle of the past decade, two efforts began to advance technologies for adaptive x-ray telescopes: The Generation-X (Gen-X) concept studies in the United States, and the Smart X-ray Optics (SXO) Basic Technology project in the United Kingdom. This paper discusses relevant technological issues and summarizes progress toward adaptive x-ray telescopes.

  15. Hard X ray imaging telescope

    NASA Astrophysics Data System (ADS)

    Lubin, P.

    1990-03-01

    This final report covers the work carried out under the LLNL Contract Number B063682, Subcontractor Regents University of California at Santa Barbara. The research carried out under this contract involves the construction of a telemetry, target acquisition and guidance system, and of a light-weight gondola to house an x ray spectrometer. This work is part of the design and construction of the balloon experiment, GRATIS, which will perform the first arcminute imaging of cosmic sources in the 30 to 200 keV energy band. Observations conducted with GRATIS are expected to provide data relevant to several key problems in high energy astrophysics including the physical processes responsible for the high energy tail observed in the soft gamma-ray spectra of clusters of galaxies and the origin of both the diffuse and point source components of the gamma-ray emission from the Galactic Center. This report discusses the scientific motivations for this experiment, presents several aspects of the design and construction of the hardware components, gives an overview of the stabilized platform, and demonstrates the expected performance and sensitivity.

  16. Hartman Testing of X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    Saha, Timo T.; Biskasch, Michael; Zhang, William W.

    2013-01-01

    Hartmann testing of x-ray telescopes is a simple test method to retrieve and analyze alignment errors and low-order circumferential errors of x-ray telescopes and their components. A narrow slit is scanned along the circumference of the telescope in front of the mirror and the centroids of the images are calculated. From the centroid data, alignment errors, radius variation errors, and cone-angle variation errors can be calculated. Mean cone angle, mean radial height (average radius), and the focal length of the telescope can also be estimated if the centroid data is measured at multiple focal plane locations. In this paper we present the basic equations that are used in the analysis process. These equations can be applied to full circumference or segmented x-ray telescopes. We use the Optical Surface Analysis Code (OSAC) to model a segmented x-ray telescope and show that the derived equations and accompanying analysis retrieves the alignment errors and low order circumferential errors accurately.

  17. Equal-Curvature X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    Saha, Timo T.; Zhang, William

    2002-01-01

    We introduce a new type of x-ray telescope design; an Equal-Curvature telescope. We simply add a second order axial sag to the base grazing incidence cone-cone telescope. The radius of curvature of the sag terms is the same on the primary surface and on the secondary surface. The design is optimized so that the on-axis image spot at the focal plane is minimized. The on-axis RMS (root mean square) spot diameter of two studied telescopes is less than 0.2 arc-seconds. The off-axis performance is comparable to equivalent Wolter type 1 telescopes.

  18. Continual expansion of the active-region corona observed by the Yohkoh Soft X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Uchida, Yutaka; Mcallister, Alan; Strong, Keith T.; Ogawara, Yoshiaki; Shimizu, Toshifumi; Matsumoto, Ryoji; Hudson, Hugh S.

    1992-01-01

    We have found from the observations of the Yohkoh Soft X-ray Telescope (SXT) that the corona above active regions expands occasionally, and almost continually in the cases of 'active' active regions. The key to this discovery has been a movie representation of the Yohkoh SXT data, which, for the first time, provides adequate sampling and continuity for this purpose. The movies show ubiquitous expansions above the active regions, with velocities in the range of a few to a few tens km/s. The expansion appears to preserve the overall structure of the active-region corona. This finding of almost continual expansion of the active-region corona may affect some of the basic ideas concerning active regions, as well as those of the mass-loss from the Sun and Sunlike stars.

  19. The microchannel x-ray telescope status

    NASA Astrophysics Data System (ADS)

    Götz, D.; Meuris, A.; Pinsard, F.; Doumayrou, E.; Tourrette, T.; Osborne, J. P.; Willingale, R.; Sykes, J. M.; Pearson, J. F.; Le Duigou, J. M.; Mercier, K.

    2016-07-01

    We present design status of the Microchannel X-ray Telescope, the focussing X-ray telescope on board the Sino- French SVOM mission dedicated to Gamma-Ray Bursts. Its optical design is based on square micro-pore optics (MPOs) in a Lobster-Eye configuration. The optics will be coupled to a low-noise pnCCD sensitive in the 0.2{10 keV energy range. With an expected point spread function of 4.5 arcmin (FWHM) and an estimated sensitivity adequate to detect all the afterglows of the SVOM GRBs, MXT will be able to provide error boxes smaller than 60 (90% c.l.) arc sec after five minutes of observation.

  20. Observations of X-ray jets with the Yohkoh Soft X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Shibata, Kazunari; Ishido, Yoshinori; Acton, Loren W.; Strong, Keith T.; Hirayama, Tadashi; Uchida, Yutaka; Mcallister, Alan H.; Matsumoto, Ryoji; Tsuneta, Saku; Shimizu, Toshifumi

    1992-01-01

    The features of the multiple X-ray jets in the solar corona, revealed by the time series of the Yohkoh Soft X-ray Telescope images are described. The typical size of a jet was from 5 x 10 exp 3 to 4 x 10 exp 5 km, the translational velocity was 30-300 km/s, and the corresponding kinetic energy was estimated to be from 10 exp 25 to 10 exp 28 erg. Many of the jets were found to be associated with flares in X-ray bright points, emerging flux regions, or active regions, and they sometimes occurred several times from the same X-ray feature. One of the jets associated with a flaring bright point was identified as being an H-alpha surge.

  1. High-Resolution X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    ODell, Stephen L.; Brissenden, Roger J.; Davis, William; Elsner, Ronald F.; Elvis, Martin; Freeman, Mark; Gaetz, Terry; Gorenstein, Paul; Gubarev, Mikhail V.

    2010-01-01

    Fundamental needs for future x-ray telescopes: a) Sharp images => excellent angular resolution. b) High throughput => large aperture areas. Generation-X optics technical challenges: a) High resolution => precision mirrors & alignment. b) Large apertures => lots of lightweight mirrors. Innovation needed for technical readiness: a) 4 top-level error terms contribute to image size. b) There are approaches to controlling those errors. Innovation needed for manufacturing readiness. Programmatic issues are comparably challenging.

  2. The x-ray telescope of CAST

    NASA Astrophysics Data System (ADS)

    Kuster, M.; Bräuninger, H.; Cebrián, S.; Davenport, M.; Eleftheriadis, C.; Englhauser, J.; Fischer, H.; Franz, J.; Friedrich, P.; Hartmann, R.; Heinsius, F. H.; Hoffmann, D. H. H.; Hoffmeister, G.; Joux, J. N.; Kang, D.; Königsmann, K.; Kotthaus, R.; Papaevangelou, T.; Lasseur, C.; Lippitsch, A.; Lutz, G.; Morales, J.; Rodríguez, A.; Strüder, L.; Vogel, J.; Zioutas

    2007-06-01

    The CERN Axion Solar Telescope (CAST) has been in operation and taking data since 2003. The main objective of the CAST experiment is to search for a hypothetical pseudoscalar boson, the axion, which might be produced in the core of the sun. The basic physics process CAST is based on is the time inverted Primakoff effect, by which an axion can be converted into a detectable photon in an external electromagnetic field. The resulting x-ray photons are expected to be thermally distributed between 1 and 7 keV. The most sensitive detector system of CAST is a pn-CCD detector combined with a Wolter I type x-ray mirror system. With the x-ray telescope of CAST a background reduction of more than 2 orders of magnitude is achieved, such that for the first time the axion photon coupling constant gaγγ can be probed beyond the best astrophysical constraints gaγγ < 1 × 10-10 GeV-1.

  3. Hard X-Ray And Wide Focusing Telescopes

    NASA Technical Reports Server (NTRS)

    Gorenstein, Paul; Johnson, William B. (Technical Monitor)

    2001-01-01

    The development of a hard X-ray telescope requires new technology for both substrates and coatings. Our activities in these two areas were carried out virtually in parallel during most of the past few years. They are converging on the production of our first integral conical, substrate electroformed mirror that will be coated with a graded d-spacing multilayer. Its imaging properties and effective area will be measured in hard X-ray beams. We discuss each of these activities separately in the following two sections.

  4. Multispectral glancing incidence X-ray telescope

    NASA Technical Reports Server (NTRS)

    Hoover, R. B. (Inventor)

    1986-01-01

    A multispectural glancing incidence X-ray telescope is illustrated capable of broadband, high-resolution imaging of solar and stellar X-ray and extreme ultraviolet radiation sources which includes a primary optical system preferably of the Wolter I type having a primary mirror system. The primary optical system further includes an optical axis having a primary focus at which the incoming radiation is focused by the primary mirrors. A plurality of ellipsoidal mirrors are carried at an inclination to the optical axis behind the primary focus. A rotating carrier is provided on which the ellipsoidal mirrors are carried so that a desired one of the ellipsoidal mirrors may be selectively positioned in front of the incoming radiation beam. In the preferred embodiment, each of the ellipsoidal mirrors has an identical concave surface carrying a layered synthetic microstructure coating tailored to reflect a desired wavelength of 1.5A or longer. Each of the identifical ellipsoidal mirrors has a second focus at which a detector is carried. Thus the different wavelength image is focused upon the detector irregardless of which mirror is positioned in front of the radiation beam.

  5. Multispectral glancing incidence X-ray telescope

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B. (Inventor)

    1990-01-01

    A multispectral glancing incidence X-ray telescope is illustrated capable of broadband, high-resolution imaging of solar and stellar X-ray and extreme ultraviolet radiation sources which includes a primary optical system preferably of the Wolter I type having a primary mirror system (20, 22). The primary optical system further includes an optical axis (24) having a primary focus (F1) at which the incoming radiation is focused by the primary mirrors. A plurality of ellipsoidal mirrors (30a, 30b, 30cand 30d) are carried at an inclination to the optical axis behind the primary focus (F1). A rotating carrier (32) is provided on which the ellipsoidal mirrors are carried so that a desired one of the ellipsoidal mirrors may be selectively positioned in front of the incoming radiation beam (26). In the preferred embodiment, each of the ellipsoidal mirrors has an identical concave surface carrying a layered synthetic microstructure coating tailored to reflect a desired wavelength of 1.5 .ANG. or longer. Each of the identical ellipsoidal mirrors has a second focus (F2) at which a detector (16) is carried. Thus the different wavelength image is focused upon the detector irregardless of which mirror is positioned in front of the radiation beam. In this manner, a plurality of low wavelengths in a wavelength band generally less than 30 angstroms can be imaged with a high resolution.

  6. Wide field x-ray telescopes: Detecting x-ray transients/afterglows related to GRBs

    SciTech Connect

    Hudec, Rene; Pina, Ladislav; Inneman, Adolf; Gorenstein, Paul

    1998-05-16

    The recent discovery of X-ray afterglows of GRBs opens the possibility of analyses of GRBs by their X-ray detections. However, imaging X-ray telescopes in current use mostly have limited fields of view. Alternative X-ray optics geometries achieving very large fields of view have been theoretically suggested in the 70's but not constructed and used so far. We review the geometries and basic properties of the wide-field X-ray optical systems based on one- and two-dimensional lobster-eye geometry and suggest technologies for their development and construction. First results of the development of double replicated X-ray reflecting flats for use in one-dimensional X-ray optics of lobster-eye type are presented and discussed. The optimum strategy for locating GRBs upon their X-ray counterparts is also presented and discussed.

  7. The Solar-A soft X-ray telescope experiment

    NASA Technical Reports Server (NTRS)

    Acton, L.; Bruner, M.; Brown, W.; Lemen, J.; Hirayama, T.

    1988-01-01

    The Japanese Solar-A mission for the study of high energy solar physics is timed to observe the sun during the next activity maximum. This small spacecraft includes a carefully coordinated complement of instruments for flare studies. In particular, the soft X-ray telescope (SXT) will provide X-ray images of flares with higher sensitivity and time resolution than have been available before. This paper describes the scientific capabilities of the SXT and illustrates its application to the study of an impulsive compact flare.

  8. Orthogonal Mirror Telescopes for X-ray Astronomy.

    PubMed

    Vanspeybroeck, L P; Chase, R C; Zehnpfennig, T F

    1971-04-01

    Crossed mirror telescopes are presented as an alternative to the present telescope systems used in x-ray astronomy. These instruments generally have a higher x-ray collecting efficiency but a poorer angular resolution than the more conventional paraboloid-hyperboloid telescopes. They also can be made more easily and quickly as was demonstrated by a recent rocket flight that used a simplified mirror design with only one-dimensional focusing.

  9. Wide Field X-Ray Telescope Mission Concept Study Results

    NASA Technical Reports Server (NTRS)

    Hopkins, R. C.; Thomas, H. D.; Fabisinski, L. L.; Baysinger, M.; Hornsby, L. S.; Maples, C. D.; Purlee, T. E.; Capizzo, P. D.; Percy, T. K.

    2014-01-01

    The Wide Field X-Ray Telescope (WFXT) is an astrophysics mission concept for detecting and studying extra-galactic x-ray sources, including active galactic nuclei and clusters of galaxies, in an effort to further understand cosmic evolution and structure. This Technical Memorandum details the results of a mission concept study completed by the Advanced Concepts Office at NASA Marshall Space Flight Center in 2012. The design team analyzed the mission and instrument requirements, and designed a spacecraft that enables the WFXT mission while using high heritage components. Design work included selecting components and sizing subsystems for power, avionics, guidance, navigation and control, propulsion, structures, command and data handling, communications, and thermal control.

  10. A normal incidence X-ray telescope sounding rocket payload

    NASA Technical Reports Server (NTRS)

    Golub, L.

    1985-01-01

    Progress is reported on the following major activities on the X-ray telescope: (1) complete design of the entire telescope assembly and fabrication of all front-end components was completed; (2) all rocket skin sections, including bulkheads, feedthroughs and access door, were specified; (3) fabrication, curing and delivery of the large graphite-epoxy telescope tube were completed; (4) an engineering analysis of the primary mirror vibration test was completed and a decision made to redesign the mirror attachment system to a kinematic three-point mount; (5) detail design of the camera control, payload and housekeeping electronics were completed; and (6) multilayer mirror plates with 2d spacings of 50 A and 60 A were produced.

  11. The X-ray properties of normal galaxies. What do we know and what can we learn with the next generation of X-ray telescopes?. [spaceborne telescope

    NASA Technical Reports Server (NTRS)

    Fabbiano, G.

    1985-01-01

    Einstein Observatory results are used to assess the possibilities of spaceborne X-ray astronomy projects such as XMM (ESA) and AXAF (NASA). Einstein observations show that normal galaxies of all morphological types are spatially extended sources of X-ray emission with 0.5 to 3.0 keV X-ray luminosities of 10 to the 39th to 41st power erg/sec. X-ray telescopes can study the end products of stellar evolution in galaxies of different morphological types. Phenomena linked to starburst nuclear activity can best be detected and studied in X-ray. Hot coronae or a hot phase of the interstellar medium can only be studied through their X-ray emission. It is shown that high spatial resolution is essential for studying normal galaxies and identifying different emission regions. Good spectral sensitivity and spectral imaging capability are essential for gaining a deeper understanding of the phenomena at work.

  12. GRBs and Lobster Eye X-Ray Telescopes

    NASA Astrophysics Data System (ADS)

    Hudec, R.; Pina, L.; Marsikova, V.; Inneman, A.

    2013-07-01

    A large majority of GRBs exhibit X-ray emission. In addition, a dedicated separate group of GRB, the XRFs, exists which emission dominates in the X-ray spectral range. And the third group of GRB related objects (yet hypothetical) are the group of off-axis observed GRBs (orphan afterglows). These facts justify the consideration of an independent experiment for monitoring, detection and analyses of GRBs and others fast X-ray transients in X-rays. We will present and discuss such experiment based on wide-field X-ray telescopes of Lobster Eye type. We show that the wide field and fine sensitivity of Lobster Eye X-ray All-Sky Monitor make such instruments important tools in study of GRBs.

  13. Toward Large-Area Sub-Arcsecond X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    O'Dell, Stephen L.; Aldcroft, Thomas L.; Allured, Ryan; Atkins, Carolyn; Burrows, David N.; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing; Cotroneo, Vincenzo; Elsner, Ronald F.; Graham, Michael E.; Gubarev, Mikhail V.; Heilmann, Ralf K.; Johnson-Wilke, Raegan L.; Kilaru, Kiranmayee; Kolodziejczak, Jeffrey J.; McMuldroch, Stuart; Ramsey, Brian D.; Reid, Paul B.; Riveros, Raul E.; Roche, Jacqueline M.; Saha, Timo T.; Schattenburg, Mark L.; Schwartz, Daniel A.; Trolier-McKinstry, Susan E.; Ulmer, Melville P.; Vaynman, Semyon; Vikhlinin, Alexey; Wang, Xiaoli; Weisskopf, Martin C.; Wilke, Rudeger H. T.; Zhang, William W.

    2014-01-01

    The future of x-ray astronomy depends upon development of x-ray telescopes with larger aperture areas (>1 sq m) and finer angular resolution(<1).Combined with the special requirements of nested grazing incidence optics, the mass and envelope constraints of spaceborne telescopes render such advances technologically challenging. Achieving this goal will require precision fabrication, alignment, mounting, and assembly of large areas (>100 sq m) of lightweight (1 kg/sq m areal density) high quality mirrors-possibly entailing active (in-space adjustable) alignment and figure correction. This paper discusses relevant programmatic and technological issues and summarizes progress toward large area sub-arcsecond x-ray telescopes. Key words: X-ray telescopes, x-ray optics, active optics, electroactive devices, silicon mirrors, differential deposition, ion implantation.

  14. Optical design for a survey x-ray telescope

    NASA Astrophysics Data System (ADS)

    Saha, Timo T.; Zhang, William W.; McClelland, Ryan S.

    2014-07-01

    Optical design trades are underway at the Goddard Space Flight Center to define a telescope for an x-ray survey mission. Top-level science objectives of the mission include the study of x-ray transients, surveying and long-term monitoring of compact objects in nearby galaxies, as well as both deep and wide-field x-ray surveys. In this paper we consider Wolter, Wolter-Schwarzschild, and modified Wolter-Schwarzschild telescope designs as basic building blocks for the tightly nested survey telescope. Design principles and dominating aberrations of individual telescopes and nested telescopes are discussed and we compare the off-axis optical performance at 1.0 KeV and 4.0 KeV across a 1.0 degree full field-of-view.

  15. Optical Design for a Survey X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Saha, Timo T.; Zhang, William W.; McClelland, Ryan S.

    2014-01-01

    Optical design trades are underway at the Goddard Space Flight Center to define a telescope for an x-ray survey mission. Top-level science objectives of the mission include the study of x-ray transients, surveying and long-term monitoring of compact objects in nearby galaxies, as well as both deep and wide-field x-ray surveys. In this paper we consider Wolter, Wolter-Schwarzschild, and modified Wolter-Schwarzschild telescope designs as basic building blocks for the tightly nested survey telescope. Design principles and dominating aberrations of individual telescopes and nested telescopes are discussed and we compare the off-axis optical performance at 1.0 KeV and 4.0 KeV across a 1.0-degree full field-of-view.

  16. Fabrication of X-ray telescopes for sounding rocket flights

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Two X-ray telescopes and two detector systems were fabricated, and one of the telescopes (15 in. diameter, Wolter type I telescope) was flown on two sounding rocket flights. The telescopes were fabricated using the diamond point technique which provided the accurate figure of the mirrors to about a focal plane blur of 0.5 arc minutes. The 15 in. telescope mirrors were polished using standard polishing techniques to remove tooling marks from the diamond turning, then chemically polished to bring the X-ray reflectivity up to nearly the theoretical values. The optical image formed by the 15 in. telescope was found to produce a blur of about 40 arc seconds for a parallel beam of incoming laser light. The first flight of the telescope produced an X-ray image of Capella which indicated that the X-ray image was blurred to the extent of about 2 arc minutes. This additional image degradation was due to a slight error in focusing the X-ray image onto the detector.

  17. Chandra X-Ray and Hubble Space Telescope Imaging of Optically Selected Kiloparsec-scale Binary Active Galactic Nuclei. II. Host Galaxy Morphology and AGN Activity

    NASA Astrophysics Data System (ADS)

    Shangguan, Jinyi; Liu, Xin; Ho, Luis C.; Shen, Yue; Peng, Chien Y.; Greene, Jenny E.; Strauss, Michael A.

    2016-05-01

    Binary active galactic nuclei (AGNs) provide clues to how gas-rich mergers trigger and fuel AGNs and how supermassive black hole (SMBH) pairs evolve in a gas-rich environment. While significant effort has been invested in their identification, the detailed properties of binary AGNs and their host galaxies are still poorly constrained. In a companion paper, we examined the nature of ionizing sources in the double nuclei of four kiloparsec-scale binary AGNs with redshifts between 0.1 and 0.2. Here, we present their host galaxy morphology based on F336W (U-band) and F105W (Y-band) images taken by the Wide Field Camera 3 on board the Hubble Space Telescope. Our targets have double-peaked narrow emission lines and were confirmed to host binary AGNs with follow-up observations. We find that kiloparsec-scale binary AGNs occur in galaxy mergers with diverse morphological types. There are three major mergers with intermediate morphologies and a minor merger with a dominant disk component. We estimate the masses of the SMBHs from their host bulge stellar masses and obtain Eddington ratios for each AGN. Compared with a representative control sample drawn at the same redshift and stellar mass, the AGN luminosities and Eddington ratios of our binary AGNs are similar to those of single AGNs. The U - Y color maps indicate that clumpy star-forming regions could significantly affect the X-ray detection of binary AGNs, e.g., the hardness ratio. Considering the weak X-ray emission in AGNs triggered in merger systems, we suggest that samples of X-ray-selected AGNs may be biased against gas-rich mergers. Based, in part, on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program number GO 12363.

  18. Telescope Scientist on the Advanced X-Ray Astrophysics Observatory

    NASA Technical Reports Server (NTRS)

    VanSpeybroeck, Leon

    1999-01-01

    The most important activity during this reporting period was the calibration of the AXAF High Resolution Mirror Assembly (HRMA) and the analysis of the copious data which were obtained during that project. The calibration was highly successful, and will result in the AXAF being by far the best calibrated X-ray observatory ever flown, and more accurate results by all of its users. This period also included participation in the spacecraft alignment and assembly activities and final flight readiness reviews. The planning of the first year of Telescope Scientist AXAF observations also was accomplished. The Telescope Scientist team also served as a technical resource for various problems which were encountered during this period. Many of these contributions have been documented in memoranda sent to the project.

  19. Cosmic X-ray telescope for ARIES rocket observations

    NASA Technical Reports Server (NTRS)

    Catura, R. C.; Acton, L. W.; Berthelsdorf, R.; Culhane, J. L.; Sanford, P. W.; Franks, A.

    1979-01-01

    A rocket-borne Wolter Type I X-ray telescope having a focal length of 2.3m, an entrance aperture of 66cm and a geometrical area of 380cm2 is nearing completion. The telescope mirrors are formed by diamond turning their figures into forged aluminum substrates of 5083 alloy. These diamond-turned substrates are subsequently plated with a thin coating of electroless nickel and polished to obtain the final X-ray reflecting surfaces. Details of the rocket payload, the X-ray telescope, its calculated response and the experience gained in selecting the mirror substrate alloy are discussed and the current status of the telescope is reviewed.

  20. Detection of soft X-rays from Alpha Lyrae and Eta Bootis with an imaging X-ray telescope

    NASA Technical Reports Server (NTRS)

    Topka, K.; Fabricant, D.; Harnden, F. R., Jr.; Gorenstein, P.; Rosner, R.

    1979-01-01

    Results are presented for observations of Alpha Lyr (Vega) and Eta Boo with an imaging X-ray telescope during two rocket flights. It is found that Vega and Eta Boo are soft X-ray sources with respective luminosities of approximately 3 x 10 to the 28th erg/s (0.15-0.8 keV) and 1 x 10 to the 29th erg/s (0.15-1.5 keV). Surface X-ray luminosities of about 640,000 erg/sq cm per sec for Vega and 300,000 erg/sq cm per sec for Eta Boo are estimated and shown to fall within the range of solar coronal X-ray emission. It is concluded that in view of the substantially larger surface areas of these stars, the relatively large total soft X-ray luminosity (as compared with that of the sun) can in both cases be understood as resulting from a moderately active corona, although the Vega observation is in severe conflict with simple models for X-ray emission from single main-sequence stars.

  1. Continuous Upflow of Plasmas at the Edge of an Active Region as Revealed by the X-ray Telescope (XRT) aboard Hinode

    NASA Astrophysics Data System (ADS)

    Sakao, Taro; Kano, R.; Narukage, N.; Kotoku, J.; Bando, T.; DeLuca, E. E.; Lundquist, L. L.; Golub, L.; Kubo, M.; Katsukawa, Y.; Tsuneta, S.; Hara, H.; Matsuzaki, K.; Shimojo, M.; Shibasaki, K.; Shimizu, T.; Nakatani, I.

    2007-05-01

    We present X-ray imaging observations with Hinode X-Ray Telescope (XRT) of an active region NOAA AR 10942 made in the period of 20-22 February 2007. A prominent feature that drew our particular attention is that there revealed continuous upflow of soft-X-ray-emitting plasmas along apparently-open field lines towards the outer corona emanating from the edge of the active region. The field lines are originated from an ensamble of small spots of following polarity, and are located at a border between the active region and an adjacent equatorial coronal hole(s) located to the east. The upflow was observed to be continuous throughout the three days of observation intervals with projected velocity of 140 km/s, accompanied with undulating motion of the field lines. We assert that these upflowing plasmas would be a possible source of slow solar wind material, which supports a foresighted notion which grew out of interplanetary scintillation observations that slow solar wind most likely has its origin in the vicinity of active regions with large flux expansion (Kojima et al. 1999). A preliminaty analysis indicates that the temperature of the upflowing material near the base of the field lines is 1.3 MK with number density of 2 × 109 /cm3. Assuming that all the material is to escape to the interplanetary space, this leads to a mass loss rate of 2 × 1011 g/s which amounts to a good fraction of the total mass loss rate for solar wind. It is noteworthy that, even apart from this unique upflow, we see continuous (up)flows of plasmas anywhere around (surrounding) the active region. Details of the upflow will be presented and their possible implication to slow solar wind discussed.

  2. X-Ray Telescope Onboard Astro-E. II. Ground-Based X-Ray Characterization.

    PubMed

    Shibata, R; Ishida, M; Kunieda, H; Endo, T; Honda, H; Misaki, K; Ishida, J; Imamura, K; Hidaka, Y; Maeda, M; Tawara, Y; Ogasaka, Y; Furuzawa, A; Watanabe, M; Terashima, Y; Yoshioka, T; Okajima, T; Yamashita, K; Serlemitsos, P J; Soong, Y; Chan, K W

    2001-08-01

    X-ray characterization measurements of the x-ray telescope (XRT) onboard the Astro-E satellite were carried out at the Institute of Space and Astronautical Science (Japan) x-ray beam facility by means of a raster scan with a narrow x-ray pencil beam. The on-axis half-power diameter (HPD) was evaluated to be 1.8?-2.2?, irrespective of the x-ray energy. The on-axis effective areas of the XRTs for x-ray imaging spectrometers (XISs) were approximately 440, 320, 240, and 170 cm(2) at energies of 1.49, 4.51, 8.04, and 9.44 keV, respectively. Those of the x-ray spectrometer (XRS) were larger by 5-10%. The replication method introduced for reflector production significantly improved the imaging capability of the Advanced Satellite for Cosmology and Astrophyics (ASCA) XRT, whose HPD is ~3.6?. The increase in the effective area by a factor of 1.5-2.5, depending upon the x-ray energy, compared with that of the ASCA, was brought about by mechanical scale up and longer focal lengths. The off-axis HPDs were almost the same as those obtained on the optical axis. The field of view is defined as the off-axis angle at which the effective area becomes half of the on-axis value. The diameter of the field of view was ~19? at 1.49 keV, decreasing with increasing x-ray energy, and became ~13? at 9.44 keV. The intensity of stray light and the distribution of this kind of light on the focal plane were measured at the large off-axis angles 30? and 60?. In the entire XIS field of view (25.4 mm x 25.4 mm), the intensity of the stray light caused by a pointlike x-ray source became at most 1% of the same pointlike source that was on the optical axis.

  3. Early Results from the YOHKOH Soft X-ray Telescope

    NASA Astrophysics Data System (ADS)

    Bruner, M. E.; Acton, L. W.; Lemen, J.; Hirayama, T.; Tsuneta, S.

    1992-05-01

    The The Soft X-ray Telescope on the Yohkoh satellite, launched by Japan on August 30, 1992, has proved to be a resounding success. It is providing a wealth of new information and many surprises, both on flares and on the behavior of the solar corona. Performance of the telescope has met or exceed our most optimistic expectations and it appears to be in perfect focus. Unlike the Skylab instruments, the Yohkoh telescope is not limited by a finite supply of film, permitting long sequences of images to be made with relatively high time resolution. Repetition rates for a given exposure / filter combination are typically a few seconds per frame to a few minutes per frame, depending on the selected field size. Movies assembled from long exposure sequences have shown the corona to be even more dynamic than expected. Major re-structuring, involving large fractions of the visible corona, can take place in an hour or two. Smaller regions are even more dynamic, changing almost continuously. Movies, created from long exposure sequences, have demonstrated the fundamental importance of large-scale coronal loops in connecting widely separated regions such that activity in one region quickly affects the physical conditions at remote sites. The images also show that the majority of the loops have nearly constant cross sections along their lengths, rather than one that increases with height. Several X-class flares have been observed; the surprising result is that they do not appear to be very dynamic in soft X-rays. The flare kernels seem to consist of compact loop structures that brighten and then fade without changing size or shape. Bright points are not as prominent as in the Skylab images; a result of using a CCD (a linear detector) rather than film which has a logarithmic response. The other instruments on Yohkoh are producing equally exciting results; it seems clear that the Yohkoh mission will produce many major advances in our knowledge of the flare mechanism.

  4. CHANDRA X-RAY AND HUBBLE SPACE TELESCOPE IMAGING OF OPTICALLY SELECTED KILOPARSEC-SCALE BINARY ACTIVE GALACTIC NUCLEI. I. NATURE OF THE NUCLEAR IONIZING SOURCES

    SciTech Connect

    Liu, Xin; Civano, Francesca; Shen, Yue; Green, Paul; Greene, Jenny E.; Strauss, Michael A.

    2013-01-10

    Kiloparsec-scale binary active galactic nuclei (AGNs) signal active supermassive black hole (SMBH) pairs in merging galaxies. Despite their significance, unambiguously confirmed cases remain scarce and most have been discovered serendipitously. In a previous systematic search, we optically identified four kpc-scale binary AGNs from candidates selected with double-peaked narrow emission lines at z = 0.1-0.2. Here, we present Chandra and Hubble Space Telescope Wide Field Camera 3 (WFC3) imaging of these four systems. We critically examine and confirm the binary-AGN scenario for two of the four targets, by combining high angular resolution X-ray imaging spectroscopy with Chandra ACIS-S, better nuclear position constraints from WFC3 F105W imaging, and direct starburst estimates from WFC3 F336W imaging; for the other two targets, the existing data are still consistent with the binary-AGN scenario, but we cannot rule out the possibility of only one AGN ionizing gas in both merging galaxies. We find tentative evidence for a systematically smaller X-ray-to-[O III] luminosity ratio and/or higher Compton-thick fraction in optically selected kpc-scale binary AGNs than in single AGNs, possibly caused by a higher nuclear gas column due to mergers and/or a viewing angle bias related to the double-peak narrow-line selection. While our result lends some further support to the general approach of optically identifying kpc-scale binary AGNs, it also highlights the challenge and ambiguity of X-ray confirmation.

  5. Hard X-Ray and Wide Focusing Telescopes

    NASA Technical Reports Server (NTRS)

    Gorenstein, Paul

    1998-01-01

    Studies are being carried out to compare the performance of several different separation materials used in the replication process. This report presents the results obtained during the second year of a program which consists of replicating smooth, thin substrates, depositing multilayer coatings upon them, and evaluating their performance. Replication and multilayer coatings are both critically important to the development of focussing hard X-ray telescopes that function up to 100 keV. The activities of the current year include extending the comparison between sputtered amorphous carbon and evaporated gold to include sputtered as well as evaporated gold. The figure of merit being the smoothness of the replica which has a direct effect on the specular reflectivity. These results were obtained with epoxy replication, but they should be applicable to electroformed nickel, the process we expect to use for the ultimate replicated optics.

  6. Spectral slicing X-ray telescope with variable magnification

    NASA Technical Reports Server (NTRS)

    Hoover, R. B.; Hildner, E. (Inventor)

    1985-01-01

    A telescope for viewing high frequency radiation (soft X-ray, extreme ultraviolet) is described. This telescope has a long focal length with a selection of magnifications despite a short housing. Light enters the telescope and is reflected by the telescope's primary optical system to one of several secondary mirrors at different locations on a movable frame. The secondary mirrors have varying degrees of magnification and select narrow spectral slices of the incident radiation. Thus, both the magnification and effective focal length field of view and wavelength can be altered by repositioning the moving frame. Configurations for spaceborne applications are discussed.

  7. The Effect of X-Ray Absorption Fine Structure in Soft X-ray Astronomical Telescopes

    NASA Astrophysics Data System (ADS)

    Owens, Alan; Denby, Michael; Wells, Alan; Keay, Adam; Graessle, Dale E.; Blake, Richard L.

    1997-02-01

    Recent in-orbit measurements by high resolution soft X-ray telescopes have revealed low-level fine structure in target spectra that cannot be attributed to a celestial source. Ultimately, this can be traced to the ability of the new high spectral resolution silicon detectors to resolve X-ray absorption fine structure (XAFS) produced in the various detection subsystems. Based on measurements taken at the Daresbury Synchrotron Radiation Source (SRS) and the National Synchrotron Light Source (NSLS), we have modeled the full-up response function of the Joint European X-ray Telescope (JET-X), taking into account edge structure generated in the detectors, filters, and mirrors. It is found that unfolding celestial source spectra using a response function in which the detailed edge shapes are calculated from standard absorption cross sections leads to the generation of spectral artifacts at every absorption edge. These in turn produce unacceptably high values of χ2 in model fits for total source fluxes above ~4 × 104 counts. For JET-X, this corresponds to a source strength of ~0.4 millicrab observed for 105 s. Statistically significant ``linelike'' features are introduced into the derived source spectra with amplitudes as great as 10% of the source flux. For JET-X, these features rise above the 3 σ level for integral source exposures above ~5 × 104 source counts. The largest deviations in the residuals arise near 0.5 keV and 2.2 keV and are attributed to XAFS produced in the oxide surface layers of the CCD and the gold reflective surface of the mirrors, respectively. These results are significant for data interpretation tasks with the ASCA, JET-X, XMM, and Advanced X-Ray Astrophysics Facility (AXAF) telescopes.

  8. The soft x ray telescope for Solar-A

    NASA Technical Reports Server (NTRS)

    Brown, W. A.; Acton, L. W.; Bruner, M. E.; Lemen, J. R.; Strong, K. T.

    1989-01-01

    The Solar-A satellite being prepared by the Institute for Sapce and Astronautical Sciences (ISAS) in Japan is dedicated to high energy observations of solar flares. The Soft X Ray Telescope (SXT) is being prepared to provide filtered images in the 2 to 60 A interval. The flight model is now undergoing tests in the 1000 foot tunnel at MSFC. Launch will be in September 1991. Earlier resolution and efficiency tests on the grazing incidence mirror have established its performance in soft x rays. The one-piece, two mirror grazing incidence telescope is supported in a strain free mount separated from the focal plane assembly by a carbon-epoxy metering tube whose windings and filler are chosen to minimize thermal and hygroscopic effects. The CCD detector images both the x ray and the concentric visible light aspect telescope. Optical filters provide images at 4308 and 4700 A. The SXT will be capable of producing over 8000 of the smallest partial frame images per day, or fewer but larger images, up to 1024 x 1024 pixel images. Image sequence with two or more of the five x ray analysis filters, with automatic exposure compensation to optimize the charge collection by the CCD detector, will be used to provide plasma diagnostics. Calculations using a differential emission measure code were used to optimize filter selection over the range of emission measure variations and to avoid redundancy, but the filters were chosen primarily to give ratios that are monotonic in plasma temperature.

  9. Advanced X-Ray Telescope Mirrors Provide Sharpest Focus Ever

    NASA Astrophysics Data System (ADS)

    1997-03-01

    Performing beyond expectations, the high- resolution mirrors for NASA's most powerful orbiting X-ray telescope have successfully completed initial testing at Marshall Space Flight Center's X-ray Calibration Facility, Huntsville, AL. "We have the first ground test images ever generated by the telescope's mirror assembly, and they are as good as -- or better than -- expected," said Dr. Martin Weisskopf, Marshall's chief scientist for NASA's Advanced X-ray Astrophysics Facility (AXAF). The mirror assembly, four pairs of precisely shaped and aligned cylindrical mirrors, will form the heart of NASA's third great observatory. The X-ray telescope produces an image by directing incoming X-rays to detectors at a focal point some 30 feet beyond the telescope's mirrors. The greater the percentage of X-rays brought to focus and the smaller the size of the focal spot, the sharper the image. Tests show that on orbit, the mirror assembly of the Advanced X-ray Astrophysics Facility will be able to focus approximately 70 percent of X-rays from a source to a spot less than one-half arc second in radius. The telescope's resolution is equivalent to being able to read the text of a newspaper from half a mile away. "The telescope's focus is very clear, very sharp," said Weisskopf. "It will be able to show us details of very distant sources that we know are out there, but haven't been able to see clearly." In comparison, previous X-ray telescopes -- Einstein and Rosat -- were only capable of focusing X- rays to five arc seconds. The Advanced X-ray Telescope's resolving power is ten times greater. "Images from the new telescope will allow us to make major advances toward understanding how exploding stars create and disperse many of the elements necessary for new solar systems and for life itself," said Dr. Harvey Tananbaum, director of the Advanced X- ray Astrophysics Facility Science Center at the Smithsonian Astrophysical Observatory, in Cambridge, MA -- responsible for the telescope

  10. High Precision Assembly of Thin Mirror X-ray Telescopes

    NASA Astrophysics Data System (ADS)

    Schattenburg, Mark

    Lightweight high resolution x-ray telescope optics are one of the key technologies under development for next-generation x-ray telescopes. The ultimate goal of this effort is to realize optics with spatial resolution rivaling Chandra (<1 arc-sec) but with collecting areas that are larger by orders of magnitude. In the USA several institutions, including GSFC, MSFC, Harvard-SAO, MIT and Northwest University are working on a variety of approaches to this problem. An excellent example is the NuSTAR x-ray telescope, which teamed Cal Tech, GSFC, Columbia University and LLNL to produce a superb set of hard x-ray optics. The telescope was composed of thousands of 0.2 mm-thick glass mirrors which were epoxied into place around a spindle structure. While very light weight, this process resulted in ~1 arc min resolution. We want to achieve ~100 times better with similar mass. A group at NASA GSFC has recently demonstrated an alternative thin-glass assembly procedure that has achieved ~7 arc sec resolution with x-ray tests. Further progress towards 1 arc-sec will require mirrors with improved figure, lower stress coatings, improved alignment, better metrology, and low stress bonding. Many of the difficulties with current mirror assembly practice stem from the use of epoxy as a bonding agent. Epoxy has many disadvantages, including high shrinkage, large CTE and creep, resin aging effects, water absorption, outgassing, low tensile strength, exothermicity, and requiring large amounts of time and/or heat to cure. These effects can cause errors that become â€oefrozen in― to the bond with no possibility of correction. We propose to investigate replacing epoxy with low temperature, low shrinkage solder alloys. We use these solders in conjunction with high power, millisec-long pulses from a fiber IR laser to deliver controlled amounts of heat into the bond area. We have demonstrated that laser pulses can be used to actuate carefully designed bonds by permanently compressing

  11. Three mirror glancing incidence system for X-ray telescope

    NASA Technical Reports Server (NTRS)

    Hoover, R. B. (Inventor)

    1974-01-01

    A telescope suitable for soft X-ray astronomical observations consists of a paraboloid section for receiving rays at a grazing angle and a hyperboloid section which receives reflections from the paraboloid at a grazing angle and directs them to a predetermined point of focus. A second hyperboloid section is centrally located from the other two surfaces and positioned to reflect from its outer surface radiation which was not first reflected by the paraboloid. A shutter is included to assist in calibration.

  12. Metrology Requirements of Future X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    Gubarev, Mikhail

    2010-01-01

    Fundamental needs for future x-ray telescopes: a) Sharp images => excellent angular resolution. b) High throughput => large aperture areas. Generation-X optics technical challenges: a) High resolution => precision mirrors & alignment. b) Large apertures => lots of lightweight mirrors. Innovation needed for technical readiness: a) 4 top-level error terms contribute to image size. b) There are approaches to controlling those errors. Innovation needed for manufacturing readiness: Programmatic issues are at least as severe

  13. Software to model the performance of x-ray telescopes

    NASA Astrophysics Data System (ADS)

    Zissa, David E.; Ahmad, Anees; Feng, Chen

    1995-06-01

    A modular user-friendly computer program for the modeling of grazing-incidence type x-ray optical systems has been developed. This comprehensive computer software GRAZTRACE covers the manipulation of input data, ray tracing with reflectivity, and surface deformation effects, convolution with x-ray source shape and x-ray scattering. The program also includes the capabilities for image analysis, detector scan modeling, and graphical presentation of the results. The utilities have been developed to interface the predicted mirror structural and thermal distortions with the ray-trace. There is no commercially available (or published) program tailored for the analysis of grazing-incidence type optical systems. The GRAZTRACE program has the analysis and graphics capabilities similar to those of the standard design and analysis programs (CODE V and SYNOPSYS) for normal-incidence optical systems. This software is written in FORTRAN 77 and runs on a SUN/SPARC station. An interactive command mode version and a batch mode version of the software have been developed. The application of GRAZTRACE for the image modeling of AXAF-I (Advanced X-ray Astrophysics Facility-Imaging) telescope is also discussed.

  14. G-133: A soft X ray solar telescope

    NASA Astrophysics Data System (ADS)

    Williams, Memorie K.; Campbell, Branton; Roming, Peter W. A.; Spute, Mark K.; Moody, J. Ward

    1992-10-01

    The GOLDHELOX Project, NASA payload number G-133, is a robotic soft x ray solar telescope designed and built by an organization of undergraduate students. The telescope is designed to observe the sun at a wavelength of 171 to 181 A. Since we require observations free from atmospheric interference, the telescope will be launched in a NASA Get-Away-Special (GAS) canister with a Motorized Door Assembly (MDA). In this paper we primarily discuss the most important elements of the telescope itself. We also elaborate on some of the technical difficulties associated with doing good science in space on a small budget (about $100,000) and mention ways in which controlling the instrument environment has reduced the complexity of the system and thus saved us money.

  15. G-133: A soft x ray solar telescope

    NASA Technical Reports Server (NTRS)

    Williams, Memorie K.; Campbell, Branton; Roming, Peter W. A.; Spute, Mark K.; Moody, J. Ward

    1992-01-01

    The GOLDHELOX Project, NASA payload number G-133, is a robotic soft x ray solar telescope designed and built by an organization of undergraduate students. The telescope is designed to observe the sun at a wavelength of 171 to 181 A. Since we require observations free from atmospheric interference, the telescope will be launched in a NASA Get-Away-Special (GAS) canister with a Motorized Door Assembly (MDA). In this paper we primarily discuss the most important elements of the telescope itself. We also elaborate on some of the technical difficulties associated with doing good science in space on a small budget (about $100,000) and mention ways in which controlling the instrument environment has reduced the complexity of the system and thus saved us money.

  16. Assembly of NASA's Most Powerful X-Ray Telescope Completed

    NASA Astrophysics Data System (ADS)

    1998-03-01

    Assembly of the world's most powerful X-ray telescope, NASA's Advanced X-ray Astrophysics Facility, was completed last week with the installation of its power-generating twin solar panels. The observatory is scheduled for launch aboard Space Shuttle mission STS-93, in December 1998. The last major components of the observatory were bolted and pinned into place March 4 at TRW Space & Electronics Group in Redondo Beach, Calif., and pre-launch testing of the fully assembled observatory began March 7. "Completion of the observatory's assembly process is a big step forward toward launch scheduled for the end of this year," said Fred Wojtalik, manager of the Observatory Projects Office at NASA's Marshall Space Flight Center in Huntsville, Ala. "With all the major components in place, we are now concentrating on a thorough pre-launch checkout of the observatory." "We're delighted to reach this major milestone for the program," said Craig Staresinich, TRW's Advanced X-ray Astrophysics Facility program manager. "The entire observatory team has worked hard to get to this point and will continue an exhaustive test program to ensure mission success. We're looking forward to delivering a truly magnificent new space capability to NASA later this summer." The first pre-launch test of the Advanced X-ray Astrophysics Facility was an acoustic test, which simulated the sound pressure environment inside the Space Shuttle cargo bay during launch. A thorough electrical checkout before and after the acoustic test verifies that the observatory and its science instruments can withstand the extreme sound levels and vibrations that accompany launch. "With 10 times the resolution and 50-100 times the sensitivity of any previous X-ray telescope, this observatory will provide us with a new perspective of our universe," said the project's chief scientist, Dr. Martin Weisskopf of Marshall Center. "We'll be able to study sources of X-rays throughout the universe, like colliding galaxies and black

  17. Study of a Solar X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Golub, Leon

    1997-01-01

    The highly structured nature of the outer solar atmosphere seems to be intimately linked to the presence, at the solar surface, of magnetic fields that have been generated inside the Sun and have emerged to the surface. The corona is brightest (and also hottest) at just those locations where the magnetic field has emerged from inside the Sun. Dynamo theory predicts that strong magnetic fields will be generated deep in the solar interior and that bundles or 'ropes' of magnetic flux will float to the surface. When this happens, a magnetically bipolar region will become visible, extending above the surface in a three-dimensional structure. The field lines penetrate through the surface, showing two magnetic poles, and also exhibit a three-dimensional structure above the surface. The structure created by the field emergence is rooted in the (relatively) cool photosphere and extends through the chromosphere and transition region to the corona. Thus, the magnetic field creates a region, called an active region, which contains portions at temperatures from less than 10(exp 4) K to greater than 10(exp 6) K, and is therefore visible at wavelengths from the infrared through x-rays. The locations where the magnetic field leaves and reenters the visible surface are called the 'footpoints' of the coronal structures associated with the magnetic field. The magnetic fields themselves are not directly visible. However, the hot coronal plasma is, for the most part, constrained to follow the direction of the magnetic field lines in the atmosphere. Now, 100 years after the discovery of x-rays by Wilhelm Roentgen in 1896, we can routinely make observations of the solar corona from outside the Earth's atmosphere in this region of the electromagnetic spectrum. As shown by comparing x-ray images with magnetograms, the bright corona over these bipolar magnetic regions consists of closed structures that seem to follow the orientation of the magnetic field. Although we can see down to the

  18. Multispectral variable magnification glancing incidence x ray telescope

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B. (Inventor)

    1992-01-01

    A multispectral, variable magnification, glancing incidence, x-ray telescope capable of broadband, high resolution imaging of solar and stellar x-ray and extreme ultraviolet radiation sources is discussed. The telescope includes a primary optical system which focuses the incoming radiation to a primary focus. Two or more rotatable mirror carriers, each providing a different magnification, are positioned behind the primary focus at an inclination to the optical axis. Each carrier has a series of ellipsoidal mirrors, and each mirror has a concave surface covered with a multilayer (layered synthetic microstructure) coating to reflect a different desired wavelength. The mirrors of both carriers are segments of ellipsoids having a common first focus coincident with the primary focus. A detector such as an x-ray sensitive photographic film is positioned at the second respective focus of each mirror so that each mirror may reflect the image at the first focus to the detector at the second focus. The carriers are selectively rotated to position a selected mirror for receiving radiation from the primary optical system, and at least the first carrier may be withdrawn from the path of the radiation to permit a selected mirror on the second carrier to receive the radiation.

  19. X ray microscope/telescope test and alignment

    NASA Technical Reports Server (NTRS)

    Walker, Arthur B. C.; Hoover, Richard B.

    1991-01-01

    The tasks performed by the Center for Applied Optics (CAO) in support of the Normal Incidence Multilayer X-Ray Optics Program are detailed. The Multi-Spectral Solar Telescope Array (MSSTA) was launched on a Terrier-boosted Black Brant sounding rocket from White Sands Missile Range on 13 May 1991. High resolution images of the sun in the soft x ray to extreme ultraviolet (EUV) regime were obtained with normal-incidence Cassegrain, Ritchey-Chretien, and Herschelian telescopes mounted in the sounding rocket. MSSTA represents the first use of multilayer optics to study a very broad range of x ray and EUV solar emissions. Energy-selective properties of multilayer-coated optics allow distinct groups of emission lines to be isolated in the solar corona and transition region. Features of the near and far coronal structures including magnetic loops of plasmas, coronal plumes, coronal holes, faint structures, and cool prominences are visible in these images. MSSTA successfully obtained unprecedented information regarding the structure and dynamics of the solar atmosphere in the temperature range of 10(exp 4)-10(exp 7) K. The performance of the MSSTA has demonstrated a unique combination of ultra-high spatial resolution and spectral differentiation by use of multilayer optics.

  20. Segmented X-Ray Optics for Future Space Telescopes

    NASA Technical Reports Server (NTRS)

    McClelland, Ryan S.

    2013-01-01

    Lightweight and high resolution mirrors are needed for future space-based X-ray telescopes to achieve advances in high-energy astrophysics. The slumped glass mirror technology in development at NASA GSFC aims to build X-ray mirror modules with an area to mass ratio of approx.17 sq cm/kg at 1 keV and a resolution of 10 arc-sec Half Power Diameter (HPD) or better at an affordable cost. As the technology nears the performance requirements, additional engineering effort is needed to ensure the modules are compatible with space-flight. This paper describes Flight Mirror Assembly (FMA) designs for several X-ray astrophysics missions studied by NASA and defines generic driving requirements and subsequent verification tests necessary to advance technology readiness for mission implementation. The requirement to perform X-ray testing in a horizontal beam, based on the orientation of existing facilities, is particularly burdensome on the mirror technology, necessitating mechanical over-constraint of the mirror segments and stiffening of the modules in order to prevent self-weight deformation errors from dominating the measured performance. This requirement, in turn, drives the mass and complexity of the system while limiting the testable angular resolution. Design options for a vertical X-ray test facility alleviating these issues are explored. An alternate mirror and module design using kinematic constraint of the mirror segments, enabled by a vertical test facility, is proposed. The kinematic mounting concept has significant advantages including potential for higher angular resolution, simplified mirror integration, and relaxed thermal requirements. However, it presents new challenges including low vibration modes and imperfections in kinematic constraint. Implementation concepts overcoming these challenges are described along with preliminary test and analysis results demonstrating the feasibility of kinematically mounting slumped glass mirror segments.

  1. Goldhelox: a soft x-ray solar telescope.

    PubMed

    Durfee, D S; Moody, J W; Brady, K D; Brown, C; Campbell, B; Durfee, M K; Early, D; Hansen, E; Madsen, D W; Morey, D B; Roming, P W; Savage, M B; Eastman, P F; Jensen, V

    1995-01-01

    The Goldhelox Project is the construction and use of a near-normal incidence soft x-ray robotic solar telescope by undergraduate students at Brigham Young University. Once it is completed and tested, it will be deployed from a Get-Away-Special (GAS) canister in the bay of a space shuttle. It will image the sun at a wavelength of 171-181Å with a time resolution of 1 sec and a spatial resolution of 2.5 arcsec. The observational bandpass was chosen to image x-rays from highly ionized coronal Fe lines. The data will be an aid in better understanding the beginning phases of solar flares and how flaring relates to the physics of the corona-chromosphere transition region. Goldhelox is tentatively scheduled to fly on a space shuttle sometime in 1995 or 1996. This paper outlines the project goals, basic instrument design, and the unique aspects of making this an undergraduate endeavor.

  2. Most powerful X-ray telescope marks third anniversary

    NASA Astrophysics Data System (ADS)

    2002-08-01

    include its discovery of an X-ray ring around the Crab Nebula , finding the most distant X-ray cluster of galaxies, capturing the deepest X-ray images ever recorded and discovering a new size of black hole. Because Earth's atmosphere blocks X-rays from reaching the surface, X-ray astronomy can only be performed from space. Launched in July 1999, the Chandra Observatory travels one-third of the way to the Moon during its orbit around the Earth every 64 hours. At its highest point, Chandra's highly elliptical, or egg-shaped, orbit is 200 times higher than that of its visible-light-gathering sister, the Hubble Space Telescope. The Marshall Center manages the Chandra program, and TRW, Inc. of Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science and flight operations from Cambridge, Mass.

  3. Simulating x-ray telescopes with McXtrace: a case study of ATHENA's optics

    NASA Astrophysics Data System (ADS)

    Ferreira, Desiree D. M.; Knudsen, Erik B.; Westergaard, Niels J.; Christensen, Finn E.; Massahi, Sonny; Shortt, Brian; Spiga, Daniele; Solstad, Mathias; Lefmann, Kim

    2016-07-01

    We use the X-ray ray-tracing package McXtrace to simulate the performance of X-ray telescopes based on Silicon Pore Optics (SPO) technologies. We use as reference the design of the optics of the planned X-ray mission Advanced Telescope for High ENergy Astrophysics (ATHENA) which is designed as a single X-ray telescope populated with stacked SPO substrates forming mirror modules to focus X-ray photons. We show that is possible to simulate in detail the SPO pores and qualify the use of McXtrace for in-depth analysis of in-orbit performance and laboratory X-ray test results.

  4. The SWIFT Gamma-Ray Burst X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Hill, J. E.; Burrows, D. N.; Nousek, J. A.; Wells, A.; Chincarini, G.; Abbey, A. F.; Angelini, L.; Beardmore, A.; Brauninger, H. W.; Chang, W.

    2006-01-01

    The Swift Gamma-Ray Burst Explorer is designed to make prompt multi-wavelength observations of Gamma-Ray Bursts and GRB afterglows. The X-ray Telescope enables Swift to determine GRB positions with a few arcseconds accuracy within 100 seconds of the burst onset. The XRT utilizes a mirror set built for JET-X and an XMM-Newton/ EPIC MOS CCD detector to provide a sensitive broad-band (0.2-10 keV) X-ray imager with an effective area of more than 120 sq cm at 1.5 keV, a field of view of 23.6 x 23.6 arcminutes, and an angular resolution of 18 arcseconds (HPD). The detection sensitivity is 2x10(exp 14) erg/sq cm/s in 10(exp 4) seconds. The instrument provides automated source detection and position reporting within 5 seconds of target acquisition. It can also measure the redshifts of GRBs with Iron line emission or other spectral features. The XRT operates in an auto-exposure mode, adjusting the CCD readout mode automatically to optimize the science return as the source intensity fades. The XRT measures spectra and lightcurves of the GRB afterglow beginning about a minute after the burst and follows each burst for days or weeks. We provide an overview of the X-ray Telescope scientific background from which the systems engineering requirements were derived, with specific emphasis on the design and qualification aspects from conception through to launch. We describe the impact on cleanliness and vacuum requirements for the instrument low energy response and to maintain the high sensitivity to the fading signal of the Gamma-ray Bursts.

  5. Telescope Scientist on the Advanced X-ray Astrophysics Observatory

    NASA Technical Reports Server (NTRS)

    Smith, Carl M. (Technical Monitor); VanSpeybroeck, Leon; Tananbaum, Harvey D.

    2004-01-01

    In this period, the Chandra X-ray Observatory continued to perform exceptionally well, with many scientific observations and spectacular results. The HRMA performance continues to be essentially identical to that predicted from ground calibration data. The Telescope Scientist Team has improved the mirror model to provide a more accurate description to the Chandra observers, enabling them to reduce the systematic errors and uncertainties in their data reduction. There also has been good progress in the scientific program. Using the Telescope Scientist GTO time, we carried out an extensive Chandra program to observe distant clusters of galaxies. The goals of this program were to use clusters to derive cosmological constraints and to investigate the physics and evolution of clusters. A total of 71 clusters were observed with ACIS-I; the last observations were completed in December 2003.

  6. Broad Band X-Ray Telescope (BBXRT) Work Station in the Spacelab Payload Operations Control Center

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The primary objective of the STS-35 mission was round the clock observation of the celestial sphere in ultraviolet and X-Ray astronomy with the Astro-1 observatory which consisted of four telescopes: the Hopkins Ultraviolet Telescope (HUT); the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE); the Ultraviolet Imaging Telescope (UIT); and the Broad Band X-Ray Telescope (BBXRT). The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Teams of controllers and researchers directed on-orbit science operations, sent commands to the spacecraft, received data from experiments aboard the Space Shuttle, adjusted mission schedules to take advantage of unexpected science opportunities or unexpected results, and worked with crew members to resolve problems with their experiments. Due to loss of data used for pointing and operating the ultraviolet telescopes, MSFC ground teams were forced to aim the telescopes with fine tuning by the flight crew. This photo captures the activity of WUPPE (Wisconsin Ultraviolet Photo-Polarimeter Experiment) data review at the Science Operations Area during the mission. This image shows mission activities at the Broad Band X-Ray Telescope (BBXRT) Work Station in the Science Operations Area (SOA).

  7. A normal incidence, high resolution X-ray telescope for solar coronal observations

    NASA Technical Reports Server (NTRS)

    Golub, L.

    1984-01-01

    Efforts directed toward the completion of an X-ray telescope assembly design, the procurement of major components, and the coordination of optical fabrication and X-ray multilayer testing are reported.

  8. The Constellation-X Spectroscopy X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Petre, Robert; Content, David; Lehan, John; O'Dell, Stephen; Owens, Scott; Podgorsky, William; Stewart, Jeff; Zhang, William

    2004-01-01

    The status of technology development for the Constellation-X Spectroscopy X-ray Telescope (SXT) mirror is presented. The SXT mirror combines a large (1.6 m) aperture with modest (12 arc sec half power diameter) angular resolution and low mass (750 kg). The overall collecting area, larger than 9,600 square cm at 0.25 keV, requires high throughput, and thus nesting of a substantial number of thin reflectors. A phased development program is underway to develop reflectors, mounting and alignment approaches, and metrology techniques for components and the mirror has a whole. The latest results in all these areas are summarized, along with an overview of results of optical testing of reflector performance.

  9. Development of High Resolution Hard X-Ray Telescope with Multilayer Coatings

    NASA Technical Reports Server (NTRS)

    Gorenstein, Paul; Brinton, John C. (Technical Monitor)

    2003-01-01

    The activities that occurred during the first year of the grant were: a) completed construction of the large multilayer deposition facility; b) Coated a large number of flat substrates and the interiors of cylindrical X-ray telescope shell substrates with uniform period and depth graded periods of tungsten-silicon (W/Is) bi-layers and other coatings; c) studied the influence of various factors affecting the quality of the multilayer coatings by measuring their reflection efficiency at 8 keV and higher energy X-rays.

  10. Time Domain X-ray Astronomy with "All-Sky" Focusing Telescopes

    NASA Astrophysics Data System (ADS)

    Gorenstein, Paul

    2016-04-01

    The largest and most diverse types of temporal variations in all of astronomy occur in the soft, i.e. 0.5 to 10 keV, X-ray band. They range from millisecond QPO’s in compact binaries to year long flares from AGNs due to the absorption of a star by a SMBH, and the appearance of transient sources at decadal intervals. Models predict that at least some gravitational waves will be accompanied by an X-ray flare. A typical GRB produces more photons/sq. cm. in the soft band than it does in the Swift BAT 15 to 150 keV band. In addition the GRB X-ray fluence and knowledge of the details of the onset of the X-ray afterglow is obtained by observing the seamless transition from the active burst phase that has been attributed to internal shocks to the afterglow phases that has been attributed to external shocks. Detecting orphan X-ray afterglows will augment the event rate. With high sensitivity detectors some GRB identifications are likely to be with the youngest, most distant galaxies in the universe. Previous all-sky X-ray monitors have been non focusing limited field of view scanning instruments. An “All-Sky” (actually several ster FOV), focusing lobster-eye X-ray telescope will have much more grasp than the previous instruments and will allow a wide range of topics to be studied simultaneously. Two types of lobster-eye telescopes have been proposed. One type focuses in one dimension and uses a coded mask for resolution in the second. The other type focuses in two dimensions but has less effective area and less bandwidth. Both types are compatible with a Probe mission.

  11. Study of X-ray optics. [testing polished Kanigen coated beryllium mirror in X ray telescope on Skylark

    NASA Technical Reports Server (NTRS)

    Froechtenigt, J. F.

    1973-01-01

    The testing is reported of a polished Kanigen coated beryllium mirror in a soft X-ray telescope to be flown on a Skylark sounding rocket. This test involved inserting the telescope in a 220 foot long vacuum line and taking photographs of an X-ray resolution source. These photographs were then used to evaluate the performance of the telescope mirror as a function of distance from the focal plane and the angular distance off the telescope axis. A second test was made in which a point source was used to study the imaging characteristics by means of a pinhole and proportional counter placed in the telescope focal plane. A third test was conducted using a position sensitive detector. The efficiency and resolution was increased by polishing.

  12. Imaging the sun in hard x rays using Fourier telescopes

    NASA Technical Reports Server (NTRS)

    Campbell, J. W.

    1993-01-01

    For several years, solar flares have been observed with a variety of instruments confirming that tremendous amounts of energy are locally stored in the solar magnetic field and then rapidly released during the life of the flare. In concert with observations, theorists have attempted to describe the means by which these energetic events occur and evolve. Two competing theories have emerged and have stood the test of time. One theory describes the flare in terms of nonthermal, electron beam injection into a thick target while the other uses a thermal approach. Both theories provide results which are reasonably consistent with current observations; but to date, none have been able to provide conclusive evidence as to the validity of either model. Imaging on short time scales (1 s) and/or small size scales (1 arc s) should give definitive answers to these questions. In order to test whether a realistic telescope can indeed discriminate between models, we construct model sources based upon the thermal and the nonthermal models and calculate the emission as a function of time and energy in the range from 10 to 100 keV. In addition, we construct model telescopes representing both the spatial modulation collimator (SMC) and the rotating modulation collimator (RMC) techniques of observation using random photon counting statistics. With these two types of telescopes we numerically simulate the instrument response to the above two model flares to see if there are distinct x-ray signatures which may be discernable. We find that theoretical descriptions of the primary models of solar flares do indeed predict different hard x-ray signatures for 1 sec time scales and at 1-5 arc sec spatial resolution. However, these distinguishing signatures can best be observed early in the impulsive phase and from a position perpendicular to the plane of the loop. Furthermore, we find that Fourier telescopes with reasonable and currently attainable design characteristics can image these

  13. Soft X Ray Telescope (SXT) focus error analysis

    NASA Technical Reports Server (NTRS)

    Ahmad, Anees

    1991-01-01

    The analysis performed on the soft x-ray telescope (SXT) to determine the correct thickness of the spacer to position the CCD camera at the best focus of the telescope and to determine the maximum uncertainty in this focus position due to a number of metrology and experimental errors, and thermal, and humidity effects is presented. This type of analysis has been performed by the SXT prime contractor, Lockheed Palo Alto Research Lab (LPARL). The SXT project office at MSFC formed an independent team of experts to review the LPARL work, and verify the analysis performed by them. Based on the recommendation of this team, the project office will make a decision if an end to end focus test is required for the SXT prior to launch. The metrology and experimental data, and the spreadsheets provided by LPARL are used at the basis of the analysis presented. The data entries in these spreadsheets have been verified as far as feasible, and the format of the spreadsheets has been improved to make these easier to understand. The results obtained from this analysis are very close to the results obtained by LPARL. However, due to the lack of organized documentation the analysis uncovered a few areas of possibly erroneous metrology data, which may affect the results obtained by this analytical approach.

  14. X-Ray Monitoring of GRBs with Lobster Eye Telescopes

    SciTech Connect

    Sveda, L.; Pina, L.; Hudec, R.; Inneman, A.; Pizzichini, G.

    2004-09-28

    We present here the soft X-ray All-Sky Monitor (ASM). It is based on the current technological capabilities, sensitive in the {approx} 0.1 - 10.0 keV range with angular resolution of {approx} 3 - 4 arcmin, and has a limiting detectable flux {approx} 10-12 erg/s/cm2 for daily scans in the mentioned energy range. The ASM will play a key role in studying transient X-ray sources like XRBs, GRBs, XRFs, X-ray novae, as well as in the study of the long term variability of X-ray sources like XRBs, AGN, or stellar X-ray flares.

  15. JIM: a joint integrated module of glass x-ray optics for astronomical telescopes

    NASA Astrophysics Data System (ADS)

    Proserpio, Laura; Breunig, Elias; Friedrich, Peter; Winter, Anita; Rohé, Christian; Eder, Josef; Burwitz, Vadim; Hartner, Gisela D.; Menz, Benedikt; Civitani, Marta; Basso, Stefano; Buratti, Enrico

    2015-09-01

    For several years, the Max-Planck-Institute for extraterrestrial Physics in Germany (MPE) and the Astronomical Observatory of Brera in Italy (INAF-OAB) have been studying the slumping technology for the manufacturing of segmented glass X-ray optics for astronomy. Despite some differences in their specific approaches, the synergy of the two institutes has always been good, focusing on the common goal of developing a technology able to meet the outstanding requirements for future X-ray telescopes: i.e. large collecting areas, low mass and good angular resolution. This synergy has in the last year resulted in an active collaboration for the production of a Joint Integrated Module (JIM) that puts together the expertise of the two research groups. In particular, the indirect slumping approach of MPE has been employed for the manufacturing of X-ray mirror segments that have been integrated into a kind of X-ray Optical Unit following the approach developed at INAF-OAB. The module has then been tested in X-ray at the MPE PANTER facility, in Neuried. The several steps and the results of this joint activity are reviewed and discussed in this paper.

  16. Operation of the x-ray telescope eROSITA

    NASA Astrophysics Data System (ADS)

    Fürmetz, Maria; Predehl, Peter; Eder, Josef; Tiedemann, Lars

    2010-07-01

    The X-ray telescope eROSITA is the core instrument besides the Russian ART-XC on the Russian Spektrum-Roentgen- Gamma satellite which will be launched in 2012 to an orbit around the L2 point of the Earth-Sun-system. During both survey and pointing phase the solar panels and the antenna constrain the possible mission scenario. The scan axis is supposed to point constantly towards the earth in the survey phase. In combination with the orbit, the points of largest exposure - the scan poles - then would be areas of a few hundred deg² instead of small singularities. The background as a permanent interference factor is limiting the performance as well as transient disruptions like solar flares. Constraints on the instrument's side are amongst others vignetting, effectivity and aligning of the different components. The mission objectives and related performance imply very stringent requirements. Extremely challenging mechanical requirements in terms of mirror accuracy, alignment and dimensional stability have to be ensured by design and realized during manufacturing and integration. Although the Wolter telescope design is quite similar to those of XMM, the manufacturing of the mirrors is even more challenging due to the more unfavorable geometry of the mirrors. Mirrors, CCD-cameras and camera electronics all have their own, partly narrow working temperature ranges. Therefore accurate thermal control has to be implemented to ensure that the telescopes are performing within specification. Objectives of this work are to find the optimum mission scenario as well as certain operating parameters, taking into account all environmental boundary conditions.

  17. THE NUCLEAR SPECTROSCOPIC TELESCOPE ARRAY (NuSTAR) HIGH-ENERGY X-RAY MISSION

    SciTech Connect

    Harrison, Fiona A.; Cook, W. Rick; Forster, Karl; Grefenstette, Brian W.; Madsen, Kristin K.; Mao, Peter H.; Miyasaka, Hiromasa; Craig, William W.; Pivovaroff, Michael J.; Christensen, Finn E.; Hailey, Charles J.; Koglin, Jason E.; Mori, Kaya; Zhang, William W.; Boggs, Steven E.; Stern, Daniel; Kim, Yunjin; Giommi, Paolo; Perri, Matteo; and others

    2013-06-20

    The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 2012 June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 to 79 keV, extending the sensitivity of focusing far beyond the {approx}10 keV high-energy cutoff achieved by all previous X-ray satellites. The inherently low background associated with concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with a more than 100-fold improvement in sensitivity over the collimated or coded mask instruments that have operated in this bandpass. Using its unprecedented combination of sensitivity and spatial and spectral resolution, NuSTAR will pursue five primary scientific objectives: (1) probe obscured active galactic nucleus (AGN) activity out to the peak epoch of galaxy assembly in the universe (at z {approx}< 2) by surveying selected regions of the sky; (2) study the population of hard X-ray-emitting compact objects in the Galaxy by mapping the central regions of the Milky Way; (3) study the non-thermal radiation in young supernova remnants, both the hard X-ray continuum and the emission from the radioactive element {sup 44}Ti; (4) observe blazars contemporaneously with ground-based radio, optical, and TeV telescopes, as well as with Fermi and Swift, to constrain the structure of AGN jets; and (5) observe line and continuum emission from core-collapse supernovae in the Local Group, and from nearby Type Ia events, to constrain explosion models. During its baseline two-year mission, NuSTAR will also undertake a broad program of targeted observations. The observatory consists of two co-aligned grazing-incidence X-ray telescopes pointed at celestial targets by a three-axis stabilized spacecraft. Deployed into a 600 km, near-circular, 6 Degree-Sign inclination orbit, the observatory has now completed commissioning, and is performing consistent with pre-launch expectations. NuSTAR is now executing its primary science mission, and with an

  18. The MXT X-Ray Telescope on Board the SVOM Mission

    NASA Astrophysics Data System (ADS)

    Götz, D.

    2016-10-01

    We present the Microchannel X-ray Telescope to be flown on the SVOM mission. The MXT telescope is a compact an light focussing X-ray (0.2-10 keV) instrument based on the coupling of a micropore optics in a narrow field "Lobster -Eye" and a pn CCD.

  19. Toward Large-Area Sub-Arcsecond X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    ODell, Stephen L.; Aldcroft, Thomas L.; Allured, Ryan; Atkins, Carolyn; Burrows, David N.; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing; Cotroneo, Vincenzo; Elsner, Ronald F.; Graham, Michael E.; Gubarev, Mikhail V.; Heilmann, Ralf K.; Johnson-Wilke, Raegan L.; Kilaru, Kiranmayee; Kolodziejczak, Jeffery J.; Lillie, Charles F.; McMuldroch, Stuart; Ramsey, Brian D.; Reid, Paul B.; Riveros, Raul E.; Roche, Jacqueline M.; Saha, Timo T.; Weisskopf, Martin C.; Zhang, William W.

    2014-01-01

    The future of x-ray astronomy depends upon development of x-ray telescopes with larger aperture areas (approx. = 3 square meters) and fine angular resolution (approx. = 1 inch). Combined with the special requirements of nested grazing-incidence optics, the mass and envelope constraints of space-borne telescopes render such advances technologically and programmatically challenging. Achieving this goal will require precision fabrication, alignment, mounting, and assembly of large areas (approx. = 600 square meters) of lightweight (approx. = 1 kilogram/square meter areal density) high-quality mirrors at an acceptable cost (approx. = 1 million dollars/square meter of mirror surface area). This paper reviews relevant technological and programmatic issues, as well as possible approaches for addressing these issues-including active (in-space adjustable) alignment and figure correction.

  20. A Broad-Band X-Ray Telescope spectrum of the massive X-ray binary X Persei

    NASA Technical Reports Server (NTRS)

    Schlegel, Eric M.; Serlemitsos, Peter J.; Jahoda, Keith; Marshall, Frank; Petre, Robert; Boldt, Elihu; Mushotzky, Richard; Swank, Jean; Szymkowiak, Andrew; Smale, Alan

    1993-01-01

    The Broad Band X-Ray Telescope, covering the 0.3-12 keV bandpass with moderate spectral resolution, observed the Be/X-ray binary X Per in 1990 December during the Astro-l mission on the Space Shuttle Columbia. The data obtained are the best to date to search for lines and edges. The data are well fitted by a power-law spectrum with a high-energy cutoff. A low value for the high-energy cutoff is found, implying a slightly weaker magnetic field strength for the X-ray pulsar. No iron line is present at about 6.5 keV with an equivalent width greater than 30-40 eV. The BBXRT observation corresponded to the 'off' state of X Per's recent 'phase change'.

  1. The Nuclear Spectroscopic Telescope Array (NuSTAR) High-Energy X-ray Mission

    NASA Technical Reports Server (NTRS)

    Harrison, Fiona A.; Craig, Willliam W.; Christensen, Finn E.; Hailey, Charles J.; Zhang, William W.; Boggs, Steven E.; Stern, Daniel; Cook, W. Rick; Forster, Karl; Giommi, Paolo; Grefenstette, Brian W.; Kim, Yunjin; Kitaguchi, Takao; Koglin, Jason E.; Madsen, Kristin K.; Mao, Peter H.; Miyasaka, Hiromasa; Mori, Kaya; Perri, Matteo; Markwardt, Craig B.; Wik, Daniel R.; Hornschemeier, Anne E.; Ptak, Andrew; Rigby, Jane R.

    2013-01-01

    High-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 to 79 keV, extending the sensitivity of focusing far beyond the 10 keV high-energy cutoff achieved by all previous X-ray satellites. The inherently low background associated with concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with a more than 100-fold improvement in sensitivity over the collimated or coded mask instruments that have operated in this bandpass. Using its unprecedented combination of sensitivity and spatial and spectral resolution, NuSTAR will pursue five primary scientific objectives: (1) probe obscured active galactic nucleus (AGN) activity out to thepeak epoch of galaxy assembly in the universe (at z 2) by surveying selected regions of the sky; (2) study the population of hard X-ray-emitting compact objects in the Galaxy by mapping the central regions of the Milky Way; (3) study the non-thermal radiation in young supernova remnants, both the hard X-ray continuum and the emission from the radioactive element 44Ti; (4) observe blazars contemporaneously with ground-based radio, optical, and TeV telescopes, as well as with Fermi and Swift, to constrain the structure of AGN jets; and (5) observe line and continuum emission from core-collapse supernovae in the Local Group, and from nearby Type Ia events, to constrain explosion models. During its baseline two-year mission, NuSTAR will also undertake a broad program of targeted observations. The observatory consists of two co-aligned grazing-incidence X-ray telescopes pointed at celestial targets by a three-axis stabilized spacecraft. Deployed into a 600 km, near-circular, 6 inclination orbit, the observatory has now completed commissioning, and is performing consistent with pre-launch expectations. NuSTAR is now executing its primary science mission, and with an expected orbit lifetime of 10 yr, we anticipate proposing a guest investigator program, to begin in late 2014.

  2. Toward large-area sub-arcsecond x-ray telescopes II

    NASA Astrophysics Data System (ADS)

    O'Dell, Stephen L.; Allured, Ryan; Ames, Andrew O.; Biskach, Michael P.; Broadway, David M.; Bruni, Ricardo J.; Burrows, David N.; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing; Chung, Yip-Wah; Cotroneo, Vincenzo; Elsner, Ronald F.; Gaskin, Jessica A.; Gubarev, Mikhail V.; Heilmann, Ralf K.; Hertz, Edward; Jackson, Thomas N.; Kilaru, Kiranmayee; Kolodziejczak, Jeffrey J.; McClelland, Ryan S.; Ramsey, Brian D.; Reid, Paul B.; Riveros, Raul E.; Roche, Jacqueline M.; Romaine, Suzanne E.; Saha, Timo T.; Schattenburg, Mark L.; Schwartz, Daniel A.; Schwartz, Eric D.; Solly, Peter M.; Trolier-McKinstry, Susan; Ulmer, Melville P.; Vikhlinin, Alexey; Wallace, Margeaux L.; Wang, Xiaoli; Windt, David L.; Yao, Youwei; Ye, Shi; Zhang, William W.; Zuo, Heng

    2016-09-01

    In order to advance significantly scientific objectives, future x-ray astronomy missions will likely call for x-ray telescopes with large aperture areas (≍ 3 m2) and fine angular resolution (≍ 12). Achieving such performance is programmatically and technologically challenging due to the mass and envelope constraints of space-borne telescopes and to the need for densely nested grazing-incidence optics. Such an x-ray telescope will require precision fabrication, alignment, mounting, and assembly of large areas (≍ 600 m2) of lightweight (≍ 2 kg/m2 areal density) high-quality mirrors, at an acceptable cost (≍ 1 M$/m2 of mirror surface area). This paper reviews relevant programmatic and technological issues, as well as possible approaches for addressing these issues-including direct fabrication of monocrystalline silicon mirrors, active (in-space adjustable) figure correction of replicated mirrors, static post-fabrication correction using ion implantation, differential erosion or deposition, and coating-stress manipulation of thin substrates.

  3. Toward Large-Area Sub-Arcsecond X-Ray Telescopes II

    NASA Technical Reports Server (NTRS)

    O'Dell, Stephen L.; Allured, Ryan; Ames, Andrew O.; Biskach, Michael P.; Broadway David M.; Bruni, Ricardo J.; Burrows, David; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing; Chung, Yip-Wah; Cotroneo, Vincenzo; Elsner, Ronald F.; Gaskin, Jessica A.; Gubarev, Mikhail V.; Heilmann, Ralf K.; Hertz, Edward; Jackson, Thomas N.; Kilaru, Kiranmayee; Kolodziejczak, Jeffery J.; McClelland, Ryan S.; Ramsey, Brian D.; Reid, Paul B.; Riveros, Raul E.; Roche, Jacqueline M.; Romaine, Suzanne E.; Saha, Timo T.; Schattenburg, Mark L.; Schwartz, Daniel A.; Schwartz, Eric D.; Solly, Peter M.; Trolier-McKinstry, Susan E.; Ulmer, Mellville P.; Vikhlilin, Alexey; Wallace, Margeaux L.; Zhang, William W.

    2016-01-01

    In order to advance significantly scientific objectives, future x-ray astronomy missions will likely call for x-ray telescopes with large aperture areas (approx. = 3 sq m) and fine angular resolution (approx. = 1"). Achieving such performance is programmatically and technologically challenging due to the mass and envelope constraints of space-borne telescopes and to the need for densely nested grazing-incidence optics. Such an x-ray telescope will require precision fabrication, alignment, mounting, and assembly of large areas (approx. = 600 sq m) of lightweight (approx. = 2 kg/sq m areal density) high-quality mirrors, at an acceptable cost (approx. = 1 M$/sq m of mirror surface area). This paper reviews relevant programmatic and technological issues, as well as possible approaches for addressing these issues-including direct fabrication of monocrystalline silicon mirrors, active (in-space adjustable) figure correction of replicated mirrors, static post-fabrication correction using ion implantation, differential erosion or deposition, and coating-stress manipulation of thin substrates.

  4. Research study entitled advanced X-ray astrophysical observatory (AXAF). [system engineering for a total X-ray telescope assembly

    NASA Technical Reports Server (NTRS)

    Rasche, R. W.

    1979-01-01

    General background and overview material are presented along with data from studies performed to determine the sensitivity, feasibility, and required performance of systems for a total X-ray telescope assembly. Topics covered include: optical design, mirror support concepts, mirror weight estimates, the effects of l g on mirror elements, mirror assembly resonant frequencies, optical bench considerations, temperature control of the mirror assembly, and the aspect determination system.

  5. ASTRO-H Soft X-Ray Telescope (SXT)

    NASA Technical Reports Server (NTRS)

    Soong, Yang; Serlemitsos Peter J.; Okajima, Takashi; Hahne, Devin

    2011-01-01

    ASTRO-H is an astrophysics satellite dedicated for X-ray spectroscopic study non-dispersively and to carry out survey complementally, which will be borne out of US-Japanese collaborative effort. Among the onboard instruments there are four conically approximated Wolter-I X-ray mirrors, among which two of them are soft X-ray mirrors\\ of which the energy range is from a few hundred eV to 15 keY, currently being fabricated in the X-ray Optics Lab at Goddard Space Flight Center. The focal point instruments will be a calorimeter (SXS) and a CCD camera (SXI), respectively. The reflectors of the mirror are made of heat-formed aluminum substrate of the thickness gauged of 152 micron, 229 micron, and 305 micron of the alloy 5052 H-19, followed by epoxy replication on gold-sputtered smooth Pyrex cylindrical mandrels to acquire the X-ray reflective surface. The epoxy layer is 10 micron nominal and surface gold layer of 0.2 micron. Improvements on angular response over the Astro-El/Suzaku mirrors come from error reduction on the figure, the roundness, and the grazing angle/radius mismatching of the reflecting surface, and tighter specs and mechanical strength on supporting structure to reduce the reflector positioning and the assembly errors. In this paper, we report the results of calibration of the engineering model of SXT (EM), and project the quality of the flight mirrors.

  6. New Mission Concept Study: Energetic X-Ray Imaging Survey Telescope (EXIST)

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This Report summarizes the activity carried out under the New Mission Concept (NMC) study for a mission to conduct a sensitive all-sky imaging survey in the hard x-ray (HX) band (approximately 10-600 keV). The Energetic X-ray Imaging Survey Telescope (EXIST) mission was originally proposed for this NMC study and was then subsequently proposed for a MIDEX mission as part of this study effort. Development of the EXIST (and related) concepts continues for a future flight proposal. The hard x-ray band (approximately 10-600 keV) is nearly the final band of the astronomical spectrum still without a sensitive imaging all-sky survey. This is despite the enormous potential of this band to address a wide range of fundamental and timely objectives - from the origin and physical mechanisms of cosmological gamma-ray bursts (GRBs) to the processes on strongly magnetic neutron stars that produce soft gamma-repeaters and bursting pulsars; from the study of active galactic nuclei (AGN) and quasars to the origin and evolution of the hard x-ray diffuse background; from the nature and number of black holes and neutron stars and the accretion processes onto them to the extreme non-thermal flares of normal stars; and from searches for expected diffuse (but relatively compact) nuclear line (Ti-44) emission in uncatalogued supernova remnants to diffuse non-thermal inverse Compton emission from galaxy clusters. A high sensitivity all-sky survey mission in the hard x-ray band, with imaging to both address source confusion and time-variable background radiations, is very much needed.

  7. Light-weight glass mirror systems for future x-ray telescopes

    NASA Astrophysics Data System (ADS)

    Winter, Anita; Breunig, Elias; Burwitz, Vadim; Friedrich, Peter; Hartner, Gisela; Menz, Benedikt; Proserpio, Laura

    2013-09-01

    Future X-ray telescopes need to combine large collecting area with good angular resolution. In order to achieve these aims within the mass limit, light-weight materials are needed for mirror production. We are developing a technology based on indirect hot slumping of thin glass segments; this method enables the production of the parabolic and hyperbolic part of the Wolter type I mirrors in one piece. Currently we use a combination of a porous ceramic for the slumping mould and the glass type D263 for the mirror material. In this study we use glasses that have been polished on one side to remove thickness variations in the glass, in order to investigate their influence on the results. We describe the experimental set-up, the slumping process and the metrology methods. Finally we present the results of an X-ray test of several integrated glass sheets, and give an outlook on future activities.

  8. A CATALOG OF SOLAR X-RAY PLASMA EJECTIONS OBSERVED BY THE SOFT X-RAY TELESCOPE ON BOARD YOHKOH

    SciTech Connect

    Tomczak, M.; Chmielewska, E. E-mail: chmielewska@astro.uni.wroc.pl

    2012-03-01

    A catalog of X-ray plasma ejections (XPEs) observed by the Soft X-ray Telescope on board the Yohkoh satellite has been recently developed in the Astronomical Institute of University of Wroclaw. The catalog contains records of 368 events observed in years 1991-2001 including movies and cross-references to associated events like flares and coronal mass ejections (CMEs). One hundred sixty-three XPEs out of 368 in the catalog were not reported until now. A new classification scheme of XPEs is proposed in which morphology, kinematics, and recurrence are considered. The relation between individual subclasses of XPEs and the associated events was investigated. The results confirm that XPEs are strongly inhomogeneous, responding to different processes that occur in the solar corona. A subclass of erupting loop-like XPEs is a promising candidate to be a high-temperature precursor of CMEs.

  9. Design and Development of Thin Plastic Foil, Conical Approximation, High Through-out X-Ray Telescope: Light Weight, Thin Plastic Foil, X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    Schnopper, Herbert W.; Barbera, Marco; Silver, Eric; Ingram, Russell; Christensen, Finn E.; Romaine, Suzanne; Cohen, Lester; Collura, Alfonso; Murray, Stephen S.; Brinton, John C. (Technical Monitor)

    2002-01-01

    We present results from a program to develop an X-ray telescope made from thin plastic shells. Our initial results have been obtained from multi-shell cylindrical lenses that are used in a point-to-point configuration to image the small focal spot of a an X-ray tube on a microchannel plate detector. We describe the steps that led up to the present design and present data from the tests that have been used to identify the properties of the plastic material that make it a suitable X-ray reflector. We discuss two applications of our technology to X-ray missions that are designed to address some of the scientific priorities set forth in NASA's long term plans for high energy astrophysics. One mission will observe in the 1 - 10 keV band, the other will extend up to ca. 100 keV.

  10. Thermal forming of substrates for the x-ray surveyor telescope

    NASA Astrophysics Data System (ADS)

    Cotroneo, Vincenzo; Allured, Ryan; Reid, Paul B.; DeRoo, Casey T.; Schwartz, Daniel A.; Marquez, Vanessa; Vikhlinin, Alexey A.; Civitani, Marta; Salmaso, Bianca; Pareschi, Giovanni

    2016-09-01

    In this paper we review the progress and current status of thermal forming activities at SAO, highlighting the most relevant technical problems and the way to solve them. These activities are devoted to the realization of mirror substrates for the X-ray surveyor mission concept, an observatory with Chandra-like angular resolution and 30 times more effective area or larger. The technology under development at SAO is based on the deposition of piezoelectric material on the back of the substrates. About 8000 mirror segments, with initial quality of 10 arcseconds or better are required for the telescope.

  11. First Images from HERO: A Hard-X-Ray Focusing Telescope

    NASA Technical Reports Server (NTRS)

    Ramsey, Brian D.; Alexander, Cheryl D.; Apple, Jeff A.; Benson, Carl M.; Dietz, Kurtis L.; Elsner, Ronald F.; Engelhaupt, Darell E.; Ghosh, Kajal K.; Kolodziejczak, Jeffery J.; ODell, Stephen L.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    We are developing a balloon-borne hard-x-ray telescope that utilizes grazing incidence optics. Termed HERO, for High-Energy Replicated Optics, the instrument will provide unprecented sensitivity in the hard-x-ray region and will achieve milliCrab-level sensitivity in a typical 3-hour balloon-flight observation and 50 microCrab sensitivity on ultra-long-duration flights. A recent proof-of-concept flight, featuring a small number of mirror shells captured the first focused hard-x-ray images of galactic x-ray sources. Full details of the payload, its expected future performance and its recent measurements are provided.

  12. Development of High Resolution Hard X-Ray Telescope with Multilayer Coatings

    NASA Technical Reports Server (NTRS)

    Brinton, John C. (Technical Monitor); Gorenstein, Paul

    2004-01-01

    The major objective of this program is the development of a focusing hard X-ray telescope with moderately high angular resolution, i .e. comparable to the telescopes of XMM-Newton. The key ingredients of the telescope are a depth graded multilayer coatings and electroformed nickel substrates that are considerably lighter weight than those of previous missions such as XMM-Newton, which have had conventional single metal layer reflective coatings and have operated at much lower energy X-rays. The ultimate target mission for this technology is the Hard X-Ray Telescope (HXT) of the Constellation X-Ray Mission. However, it is applicable to potential SMEX and MIDEX programs as well.

  13. Lost and Found: X-ray Telescope Locates Missing Matter

    NASA Astrophysics Data System (ADS)

    2005-02-01

    NASA's Chandra X-ray Observatory has discovered two huge intergalactic clouds of diffuse hot gas. These clouds are the best evidence yet that a vast cosmic web of hot gas contains the long-sought missing matter - about half of the atoms and ions in the Universe. Various measurements give a good estimate of the mass-density of the baryons - the neutrons and protons that make up the nuclei of atoms and ions - in the Universe 10 billion years ago. However, sometime during the last 10 billion years a large fraction of the baryons, commonly referred to as "ordinary matter" to distinguish them from dark matter and dark energy, have gone missing. Chandra X-ray Spectrum of Mkn 421 Chandra X-ray Spectrum of Mkn 421 "An inventory of all the baryons in stars and gas inside and outside of galaxies accounts for just over half the baryons that existed shortly after the Big Bang," explained Fabrizio Nicastro of the Harvard-Smithsonian Center for Astrophysics, and lead author of a paper in the 3 February 2005 issue of Nature describing the recent research. "Now we have found the likely hiding place of the missing baryons." Nicastro and colleagues did not just stumble upon the missing baryons - they went looking for them. Computer simulations of the formation of galaxies and galaxy clusters indicated that the missing baryons might be contained in an extremely diffuse web-like system of gas clouds from which galaxies and clusters of galaxies formed. These clouds have defied detection because of their predicted temperature range of a few hundred thousand to a million degrees Celsius, and their extremely low density. Evidence for this warm-hot intergalactic matter (WHIM) had been detected around our Galaxy, or in the Local Group of galaxies, but the lack of definitive evidence for WHIM outside our immediate cosmic neighborhood made any estimates of the universal mass-density of baryons unreliable. Chandra X-ray Image of Mkn 421 Chandra X-ray Image of Mkn 421 The discovery of much more

  14. Grazing Incidence Nickel Replicated Optics for Hard X-ray Telescopes

    NASA Technical Reports Server (NTRS)

    Peturzzo, J. J., III; Elsner, R. F.; Joy, M. K.; ODell, S. L.; Weisskopf, M. C.

    1997-01-01

    The requirements for future hard x-ray (up to 50 keV) telescopes are lightweight, high angular resolution optics with large collecting areas. Grazing incidence replicated optics are an excellent candidate for this, type of mission, providing better angular resolution, comparable area/unit mass, and simpler fabrication than multilayer-coated foils. Most importantly, the technology to fabricate the required optics currently exists. A comparison of several hard x-ray telescope designs will be presented.

  15. ASTRO-H Soft X-ray Telescope (SXT)

    NASA Astrophysics Data System (ADS)

    Soong, Yang; Serlemitsos, Peter J.; Okajima, Takashi; Hahne, Devin

    2011-09-01

    ASTRO-H is an astrophysics satellite dedicated for X-ray spectroscopic study non-dispersively and to carry out survey complementally, which will be borne out of US-Japanese collaborative effort. Among the onboard instruments there are four conically approximated Wolter-I X-ray mirrors, among which two of them are soft X-ray mirrors1, of which the energy range is from a few hundred eV to 15 keV, currently being fabricated in the X-ray Optics Lab at Goddard Space Flight Center. The focal point instruments will be a calorimeter (SXS) and a CCD camera (SXI), respectively. The reflectors of the mirror are made of heat-formed aluminum substrate of the thickness gauged of 152 μm, 229 μm, and 305 μm of the alloy 5052 H-19, followed by epoxy replication on gold-sputtered smooth Pyrex cylindrical mandrels to acquire the X-ray reflective surface. The epoxy layer is 10 μm nominal and surface gold layer of 0.2 μm. Improvements on angular response over the Astro-E1/Suzaku mirrors come from error reduction on the figure, the roundness, and the grazing angle/radius mismatching of the reflecting surface, and tighter specs and mechanical strength on supporting structure to reduce the reflector positioning and the assembly errors. In this paper, we report the results of calibration of the engineering model of SXT (EM), and project the quality of the flight mirrors.

  16. Future X-Ray Telescopes: Fresnel Lenses and Interferometry

    NASA Astrophysics Data System (ADS)

    Smith, T. L.; Romaine, S. E.

    2002-12-01

    Science goals are well established for the next generation X-ray observatories, such as Constellation-X1 and Xeus2, which are being planned as followups to the successful Chandra3 and XMM-Newton4, missions which were launched in 1999. Both Constellation-X and Xeus observatories, planned for launch the end of this decade, emphasize large collecting area and high spectral resolution over angular resolution. Hence their angular resolution will not equal the < ~0.5'' of Chandra, the highest angular resolution of any X-ray observatory to date. These missions indicate a new direction for future X-ray observatories: from large general purpose observatories, such as Chandra, to missions with more focused science goals and therefore more tailored designs. Just as Constellation-X and Xeus emphasize throughput and spectral resolution, there are other designs which emphasize imaging with angular resolution surpassing Chandra's already invaluable 0.5''. This will be the emphasis of the missions to follow Constellation-X5. Two of these designs, Fresnel Lenses and X-ray interferometry, present optical systems which, theoretically, can reach micro-arcsecond angular resolutions. Many obstacles have stood in the way of making these designs a reality, but technology is now being developed6 which overcomes these obstacles, opening the door to X-ray imaging at unprecedented resolution. We present basic characteristics of both optical designs as well as the type of science that would benefit most from a milliarcsecond (or better) observatory. 1http://constellation.gsfc.nasa.gov/ 2http://astro.estec.esa.nl/SA-general/Projects/XEUS/ 3http://chandra.harvard.edu/ 4http://sci.esa.int/home/xmm-newton/index.cfm 5http://maxim.gsfc.nasa.gov/ 6Cash, W., Shipley, A., Osterman, S., & Joy, M. 2000, Nature 407, 160 This work was supported in part by NSF grant AST-9731923 to the SAO Summer Intern program.

  17. The soft X-ray telescope for the SOLAR-A mission

    NASA Technical Reports Server (NTRS)

    Tsuneta, S.; Acton, L.; Bruner, M.; Lemen, J.; Brown, W.; Caravalho, R.; Catura, R.; Freeland, S.; Jurcevich, B.; Owens, J.

    1991-01-01

    The Soft X-ray Telescope (SXT) of the SOLAR-A mission is designed to produce X-ray movies of flares with excellent angular and time resolution as well as full-disk X-ray images for general studies. A selection of thin metal filters provide a measure of temperature discrimination and aid in obtaining the wide dynamic range required for solar observing. The co-aligned SXT aspect telescope will yield optical images for aspect reference, white-light flare and sunspot studies, and, possibly, helioseismology. This paper describes the capabilities and characteristics of the SXT for scientific observing.

  18. On the Design of Wide-Field X-ray Telescopes

    NASA Technical Reports Server (NTRS)

    Elsner, Ronald F.; O'Dell, Stephen L.; Ramsey, Brian D.; Weiskopf, Martin C.

    2009-01-01

    X-ray telescopes having a relatively wide field-of-view and spatial resolution vs. polar off-axis angle curves much flatter than the parabolic dependence characteristic of Wolter I designs are of great interest for surveys of the X-ray sky and potentially for study of the Sun s X-ray emission. We discuss the various considerations affecting the design of such telescopes, including the possible use of polynomial mirror surface prescriptions, a method of optimizing the polynomial coefficients, scaling laws for mirror segment length vs. intersection radius, the loss of on-axis spatial resolution, and the positioning of focal plane detectors.

  19. The Soft X-ray Telescope for Solar-A - Design evolution and lessons learned

    NASA Technical Reports Server (NTRS)

    Bruner, Marilyn E.

    1992-01-01

    The Japanese Solar-A satellite mission's Soft X-ray Telescope uses grazing-incidence optics, a CCD detector, and a pair of filter wheels for wavelength selection. A coaxially-mounted visible-light lens furnished sunspot and magnetic plage images, together with aspect information which aids in aligning the soft X-ray images with those from the satellite's Hard X-ray Telescope. Instrument electronics are microprocessor-based, and imbedded in a tightly integrated distributed system. Control software is divided between the instrument microprocessor and the spacecraft control computer.

  20. Swift X-Ray Telescope Observations of Superluminous Supernovae

    NASA Astrophysics Data System (ADS)

    Kae Batara Olaes, Melanie; Quimby, Robert

    2016-06-01

    Superluminous Supernovae (SLSNe) are a part of an emerging class of exceptionally bright supernovae with peak luminosities 10 times brighter than typical Type Ia supernovae. Similar to supernovae, SLSNe are divided into two subclasses: hydrogen poor SLSN-I and hydrogen rich SLSN-II. However, the luminosity of these events is far too high to be explained by the models for normal supernovae. New models developed to explain SLSNe predict high luminosity X-ray emission at late times. A consistent analysis of incoming SLSNe is essential in order to place constraints on the mechanisms behind these events. Here we present the results of X-ray analysis on SLSNe using a Bayesian method of statistical inference for low count rate events.

  1. Solar EUV, XUV and soft X-ray telescope facilities

    NASA Technical Reports Server (NTRS)

    Withbroe, G. L.

    1982-01-01

    Facility class, high resolution instrumentation can enable maximum spatial, spectral and temporal resolutions and provide understanding of the complex physical conditions in the outer solar atmosphere and the mechanisms responsible for these conditions. The scientific rationale for facility class instruments operating in the EUV, XUV, and soft X ray spectral ranges are discussed. Possible configurations for these facilities and priorities for their development are considered.

  2. The camera of the Microchannel X-ray telescope onboard the SVOM mission

    NASA Astrophysics Data System (ADS)

    Meuris, Aline; Pinsard, Frédéric; Doumayrou, Eric; Tourrette, Thierry; Götz, Diego; Carty, Mickael; Donati, Modeste; Dumaye, Luc; Goetschy, Alain; Nico, François; Meidinger, Norbert; Miessner, Danilo; Mercier, Karine

    2014-07-01

    The Microchannel X-Ray Telescope will be implemented on board the SVOM space mission to observe the afterglow of gamma-ray bursts and localize them with 2 arcmin precision. The optical system is based on microchannel plates assembling in Wolter-I configuration to focus the X-rays in the focal plane, like done for the MIXS telescope of the BepiColombo ESA mission. The sensor part is a 256 × 256 pixel pnCCD from the Max-Planck Institute for Extraterrestrial Physics for high resolution spectroscopy and high quantum efficiency over 0.2 - 10 keV energy range, based on the same technology and design as the eROSITA telescopes for the Russian-German SRG mission. CEA-Irfu (Saclay) is in charge of the design and the realization of the camera, including the focal plane, the calibration wheel, the front-end electronics, the structure housing for background shielding and the active cooling system. A prototype of the full detection chain and the acquisition system was set up. The paper presents the preliminary design of the electrical, mechanical and thermal architectures of the camera. It focuses on the fabrication and testing of the critical elements of the design and concludes on the on-going developments.

  3. X-ray optical properties of a Wolter telescope

    NASA Technical Reports Server (NTRS)

    Ondrusch, A.

    1980-01-01

    Physical properties and the fabrication sequence of a Wolter telescope are discussed. Such telescopes are intended to examine the dust scattering halos after being placed in orbit by a booster rocket launched from Australia.

  4. Wolter-schwarzschild telescopes for x-ray astronomy.

    PubMed

    Chase, R C; Vanspeybroeck, L P

    1973-05-01

    The resolution of a Wolter-Schwarzschild telescope is intrinsically superior to the resolution of the corresponding paraboloid-hyperboloid telescope. The improvement is important for high resolution and wide field telescope designs having grazing angles larger than about 1.5 degrees .

  5. Geant4 simulations of a wide-angle x-ray focusing telescope

    NASA Astrophysics Data System (ADS)

    Zhao, Donghua; Zhang, Chen; Yuan, Weimin; Zhang, Shuangnan; Willingale, Richard; Ling, Zhixing

    2017-03-01

    The rapid development of X-ray astronomy has been made possible by widely deploying X-ray focusing telescopes on board many X-ray satellites. Geant4 is a very powerful toolkit for Monte Carlo simulations and has remarkable abilities to model complex geometrical configurations. However, the library of physical processes available in Geant4 lacks a description of the reflection of X-ray photons at a grazing incident angle which is the core physical process in the simulation of X-ray focusing telescopes. The scattering of low-energy charged particles from the mirror surfaces is another noteworthy process which is not yet incorporated into Geant4. Here we describe a Monte Carlo model of a simplified wide-angle X-ray focusing telescope adopting lobster-eye optics and a silicon detector using the Geant4 toolkit. With this model, we simulate the X-ray tracing, proton scattering and background detection. We find that: (1) the effective area obtained using Geant4 is in agreement with that obtained using Q software with an average difference of less than 3%; (2) X-rays are the dominant background source below 10 keV; (3) the sensitivity of the telescope is better by at least one order of magnitude than that of a coded mask telescope with the same physical dimensions; (4) the number of protons passing through the optics and reaching the detector by Firsov scattering is about 2.5 times that of multiple scattering for the lobster-eye telescope.

  6. Thermal Properties of A Solar Coronal Cavity Observed with the X-Ray Telescope on Hinode

    NASA Technical Reports Server (NTRS)

    Reeves, Katherine K.; Gibson, Sarah E.; Kucera, Theresa A.; Hudson, Hugh S.; Kano, Ryouhei

    2011-01-01

    Coronal cavities are voids in coronal emission often observed above high latitude filament channels. Sometimes, these cavities have areas of bright X-ray emission in their centers. In this study, we use data from the X-ray Telescope (XRT) on the Hinode satellite to examine the thermal emission properties of a cavity observed during July 2008 that contains bright X-ray emission in its center. Using ratios of XRT filters, we find evidence for elevated temperatures in the cavity center. The area of elevated temperature evolves from a ring-shaped structure at the beginning of the observation, to an elongated structure two days later, finally appearing as a compact round source four days after the initial observation. We use a morphological model to fit the cavity emission, and find that a uniform structure running through the cavity does not fit the observations well. Instead, the observations are reproduced by modeling several short cylindrical cavity "cores" with different parameters on different days. These changing core parameters may be due to some observed activity heating different parts of the cavity core at different times. We find that core temperatures of 1.75 MK, 1.7 MK and 2.0 MK (for July 19, July 21 and July 23, respectively) in the model lead to structures that are consistent with the data, and that line-of-sight effects serve to lower the effective temperature derived from the filter ratio.

  7. Analysis of the 23 June 1988 flare using NIXT multilayer X-ray images. [normal incidence X-ray telescope

    NASA Technical Reports Server (NTRS)

    Golub, Leon; Herant, Marc

    1989-01-01

    Results obtained during the June 23, 1988 flight of the normal incidence X-ray telescope (NIXT) sounding rocket payload are reported. The telescope primary is 25 cm in diameter, in a 750 cm e.f.l. (f/30) Ritchey-Chretien configuration, with multilayer coatings on the optics designed to image the Fe XVI and Mg X coronal emission lines near 63.5 A. Images of the onset phase of a large (M8) Solar flare were recorded during the flight on a modified T-max 400 film manufactured by Kodak. Some of the results obtained by comparison of the NIXT data with ground-based observations of the sun obtained simultaneously to the flight are also reported.

  8. From X-Ray Telescopes to Neutron Focusing

    NASA Technical Reports Server (NTRS)

    Gubarev, M. V.; Khaykovich, B.; Ramsey, B.; Moncton, D. E.

    2011-01-01

    In the case of neutrons the refractive index is slightly less than unity for most elements and their isotopes. Consequently, thermal and cold neutrons can be reflected from smooth surfaces at grazing-incidence angles. Hence, the optical technologies developed for x-ray astronomy can be applied for neutron focusing. The focusing capabilities of grazing incidence neutron imaging optics have been successfully demonstrated using nickel mirrors. The mirrors were fabricated using an electroformed nickel replication process at Marshall Space Flight Center. Results of the neutron optics experiments will be presented. Challenges of the neutron imaging optics as well as possible applications of the optics will be discussed.

  9. Spectral slicing x-ray telescope with variable magnification

    SciTech Connect

    Hoover, R.H.; Hildner, E.

    1985-12-31

    A telescope for viewing high frequency radiation. This telescope has a long focal length with a selection of magnifications despite a short housing. Light enters the telescope and is reflected by the telescope's primary optical system and to one of several secondary mirrors at different locations on a movable frame. The secondary mirrors have varying degrees of magnification and select narrow spectral slices of the incident radiation. Thus, both the magnification and effective focal length field of view and wavelength can be altered by repositioning moving frame.

  10. Development of an x-ray telescope using the carbon fiber reinforced plastic

    NASA Astrophysics Data System (ADS)

    Awaki, Hisamitsu; Sugita, Satoshi; Ogi, Keiji; Yoshioka, Kenya; Matsumoto, Hironori; Mitsuishi, Ikuyuki; Tawara, Yuzuru

    2016-07-01

    We are developing an X-ray mirror using the CFRP as substrate in order to improve the angular resolution of tightlynested type X-ray telescope on board future X-ray satellites. We have fabricated Wolter-I designed monolithic CFRP mirrors and made improvements in the fabrication process. In the updated CFRP mirror, the half-power width of the reflection image by optical measurement was 0.8 arc-minutes on average. The measurement of the characterization of the updated CFRP mirrors at ISAS X-ray beam-line was performed in December 2015, and confirmed that the imaging quality of the CFRP mirror changed with increasing duration in vacuum chamber. We also present a current status of development of more intricate-structure CFRP substrate such as four-stage X-ray optics.

  11. X-ray structures associated with disappearing H-alpha filaments in active regions

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.

    1980-01-01

    The paper examines the relationship between active region disappearing H-alpha filaments and the associated coronal X-ray structures observed both before the disappearance event and afterwards. The events chosen for the study were selected from a list of active region X-ray transients observed in the images from the X-ray telescope on Skylab and from a list compiled by Webb (1976) of sudden disappearances of filaments during the Skylab period. Results indicate no distinction between the disappearing and the remaining active region filaments in terms of their pre-event associated X-ray emission features. However, X-ray brightenings were associated in a nearly one-to-one correspondence with disappearing portions of the filaments.

  12. A normal incidence, high resolution X-ray telescope for solar coronal observations

    NASA Technical Reports Server (NTRS)

    Golub, L.

    1984-01-01

    A Normal Incidence high resolution X-ray Telescope is reported. The design of a telescope assembly which, after fabrication, will be integrated with the mirror fabrication process is described. The assembly is engineered to fit into the Black Brant rocket skin to survive sounding rocket launch conditions. A flight ready camera is modified and tested.

  13. A high sensitivity balloon-borne X-ray telescope system

    NASA Technical Reports Server (NTRS)

    Pelling, M. R.

    1974-01-01

    A high sensitivity X-ray telescope system suitable for photometric type observations from balloon altitudes is described. The balloon gondola system is defined to include the performance requirements and the overall performance requirements of the balloon gondola support system. Diagrams of the gondola and the installed components are provided. The pointing and control system of the telescope is analyzed.

  14. Thickness variations along coronal loops observed by the Soft X-ray Telescope on Yohkoh

    NASA Technical Reports Server (NTRS)

    Klimchuk, James A.; Lemen, James R.; Feldman, Uri; Tsuneta, Saku; Uchida, Yutaka

    1992-01-01

    The paper presents preliminary results of an investigation of thickness variations along coronal loops observed with the Yohkoh Soft X-ray Telescope (SXT), using observations from ten loops selected from the SXT data. The quantitative results indicate that coronal X-ray loops do not expand. This contradicts the expectation that, if plasma loops coincide with magnetic loops, many loops must be significantly broader at their tops than at their foot points. Possible interpretations of the obtained results are proposed.

  15. Thermal Properties of Coronal Cavities as Observed by the X-Ray Telescope on Hinode

    NASA Technical Reports Server (NTRS)

    Reeves, Kathy; Gibson, S. E.; Kucera, T. A.; Hudson, H. S.; Tripathi, D.

    2010-01-01

    Coronal cavities are voids in coronal emission often observed above high latitude filament channels. Sometimes, these cavities have areas of bright X-ray emission in their centers (i.e. Hudson et al 1999). In this study, we use data from the X-ray Telescope (XRT) on Hinode to examine the thermal emission properties of two kinds of coronal cavities, those with and without enhanced emission at their centers. For cavities with bright X-ray emission in their centers, we find evidence for elevated temperatures in the cavity center. We find no obvious correlation between the presence of bright cavity cores and filament presence or eruption.

  16. The Extended Range X-Ray Telescope center director's discretionary fund report

    NASA Technical Reports Server (NTRS)

    Hoover, R. B.; Cumings, N. P.; Hildner, E.; Moore, R. L.; Tandberg-Hanssen, E. A.

    1985-01-01

    An Extended Range X-Ray Telescope (ERXRT) of high sensitivity and spatial resolution capable of functioning over a broad region of the X-ray/XUV portion of the spectrum has been designed and analyzed. This system has been configured around the glancing-incidence Wolter Type I X-ray mirror system which was flown on the Skylab Apollo Telescope Mount as ATM Experiment S-056. Enhanced sensitivity over a vastly broader spectral range can be realized by the utilization of a thinned, back-illuminated, buried-channel Charge Coupled Device (CCD) as the X-ray/XUV detector rather than photographic film. However, to maintain the high spatial resolution inherent in the X-ray optics when a CCD of 30 micron pixel size is used, it is necessary to increase the telescope plate scale. This can be accomplished by use of a glancing-incidence X-ray microscope to enlarge and re-focus the primary image onto the focal surface of the CCD.

  17. The challenge of developing thin mirror shells for future x-ray telescopes

    NASA Astrophysics Data System (ADS)

    Döhring, Thorsten; Stollenwerk, Manfred; Gong, Qingqing; Proserpio, Laura; Winter, Anita; Friedrich, Peter

    2015-09-01

    Previously used mirror technologies are not able to fulfil the requirements of future X-ray telescopes due to challenging requests from the scientific community. Consequently new technical approaches for X-ray mirror production are under development. In Europe the technical baseline for the planned X-ray observatory ATHENA is the radical new approach of silicon pore optics. NASÁs recently launched NuSTAR mission uses segmented mirrors shells made from thin bended glasses, successfully demonstrating the feasibility of the glass forming technology for X-ray mirrors. For risk mitigation also in Europe the hot slumping of thin glasses is being developed as an alternative technology for lightweight X-ray telescopes. The high precision mirror manufacturing requires challenging technical developments; several design trades and trend-setting decisions need to be made and are discussed within this paper. Some new technical and economic aspects of the intended glass mirror serial production are also studied within the recently started interdisciplinary project INTRAAST, an acronym for "industry transfer of astronomical mirror technologies". The goal of the project, embedded in a cooperation of the Max-Planck-Institute for extraterrestrial Physics and the University of Applied Sciences Aschaffenburg, is to master the challenge of producing thin mirror shells for future X-ray telescopes. As a first project task the development of low stress coatings for thin glass mirror substrates have been started, the corresponding technical approach and first results are presented.

  18. Metrology for x-ray telescope mirrors in a vertical configuration

    SciTech Connect

    Li, Haizhang; Li, Xiaodan; Grindel, M.W.

    1995-09-01

    Mirrors used in x-ray telescope systems for observations outside of the earth`s atmosphere are usually made of several thin nested shells, each formed by a pair of paraboloidal and hyperboloidal surfaces. The thin shells are very susceptible to self-weight deflection caused by gravity and are nearly impossible to test by conventional interferometric techniques. The metrology requirements for these mirrors are extremely challenging. This paper presents a prototype of a Vertical Scanning Long Trace Profiler (VSLTP) which is optimized to measure the surface figure of x-ray telescope mirrors in a vertical orientation. The optical system of the VSLTP is described. Experimental results from measurements on an x-ray telescope mandrel and tests of the accuracy and repeatability of the prototype VSLTP are presented. The prototype instrument has achieved a height measurement accuracy of about 50 nanometers with a repeatability of better than 20 nanometers, and a slope measurement accuracy of about 1 microradian.

  19. Skylab ATM/S-056 X-ray event analyzer observations versus solar flare activity: An event compilation. [tables (data)

    NASA Technical Reports Server (NTRS)

    Wilson, R. M.

    1977-01-01

    An event compilation is presented which correlates ATM/S-056 X-ray event analyzer solar observations with solar flare activity. Approximately 1,070 h of pulse height analyzed X-ray proportional counter data were obtained with the X-ray event analyzer during Skylab. During its operation, 449 flares (including 343 flare peaks) were observed. Seventy events of peak X-ray emission or = Cl were simultaneously observed by ground based telescopes, SOLRAD 9 and/or Vela, and the X-ray event analyzer. These events were observed from preflare through flare rise to peak and through flare decline.

  20. Design and mathematical analysis of a three-mirror X-ray telescope based on ATM S-056 X-ray telescope hardware

    NASA Technical Reports Server (NTRS)

    Foreman, J. W., Jr.; Cardone, J. M.

    1973-01-01

    The mathematical design of the aspheric third mirror for the three-mirror X-ray telescope (TMXRT) is presented, along with the imaging characteristics of the telescope obtained by a ray trace analysis. The present design effort has been directed entirely toward obtaining an aspheric third mirror which will be compatible with existing S-056 paraboloidal-hyperboloidal mirrors. This compatability will facilitate the construction of a prototype model of the TMXRT, since it will only be necessary to fabricate one new mirror in order to obtain a working model.

  1. The development of the μROSI X-ray telescope

    NASA Astrophysics Data System (ADS)

    Tiedemann, Lars; Breunig, Elias; Burwitz, Vadim; Fürmetz, Maria; Hartner, Gisela; Kink, Walter; Menz, Benedikt; Predehl, Peter; Röser, Hans-Peter; Schlecker, Martin; Valsecchi, Giuseppe

    2013-09-01

    The μROSI (Micro Roentgen Satellite Instrument) miniature X-ray telescope is the first X-ray telescope specifically designed for an amateur micro satellite. Its mission is to perform an all-sky survey in the soft X-ray band on board the Italian satellite Max-Valier. Due to the limitations imposed by the small size of the spacecraft, the instrument features a silicon drift detector (SDD) with very low power consumption and a focusing optics that consists of 12 nested mirror shells. With a field of view of 1°, μROSI will perform an all-sky survey flying in sun-synchronous orbit (SSO). As a secondary mission objective, the telescope will observe the Earth's upper atmosphere during the all-sky survey, potentially detecting the O2 absorption line. This paper describes the overall telescope design and gives an overview of the key components of the telescope: the mirror subsystem and the detector subsystem. All subsystems have been tested with flight-like engineering models. The results of these tests are presented in this paper. The silicon drift detector (SDD) of the μROSI telescope has been tested with a breadboard electronics and the engineering model of the electronics is currently being manufactured. The breadboard test proved that the SDD together with the specifically developed electronics is capable of measuring high resolution spectra in the soft X-ray bandwidth. One demonstrator mirror shell has been produced and tested in the PANTER X-ray test facility to verify the X-ray properties. The measurements suggest that the final μROSI mirror system fulfills all requirements for conducting its mission successfully.

  2. Structural mechanics of the solar-A Soft X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Jurcevich, B. K.; Bruner, M. E.; Gowen, K. F.

    1992-01-01

    The Soft X-ray Telescope (SXT) is one of four major instruments that constitute the payload of the NASA-Japanese mission YOHKOH (formerly known as Solar-A), scheduled to be launched in August, 1991. This paper describes the design of the SXT, the key system requirements, and the SXT optical and structural systems. Particular attention is given to the design considerations for stiffness and dimensional stability, temperature compensation, and moisture sensitivyty control. Consideration is also given to the X-ray mirror, the aspect telescope, the entrance filters, the mechanical structure design, the aft support plate and mount, the SXT finite element model, and other subsystems.

  3. Effects of Contamination Upon the Performance of X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    O'Dell, Stephen L.; Elsner, Ronald F.; Oosterbroek, Tim

    2010-01-01

    Particulate and molecular contamination can each impact the performance of x-ray telescope systems. Furthermore, any changes in the level of contamination between on-ground calibration and in-space operation can compromise the validity of the calibration. Thus, it is important to understand the sensitivity of telescope performance, especially the net effective area and the wings of the point spread function to contamination. Here, we quantify this sensitivity and discuss the flow-down of science requirements to contamination-control requirements. As an example, we apply this methodology to the International X-ray Observatory (IXO), currently under joint study by ESA, JAXA, and NASA.

  4. Current status of ASTRO-H Hard X-ray Telescopes (HXTs)

    NASA Astrophysics Data System (ADS)

    Awaki, Hisamitsu; Kunieda, Hideyo; Furuzawa, Akihiro; Haba, Yoshito; Hayashi, Takayuki; Iizuka, Ryo; Ishibashi, Kazunori; Ishida, Manabu; Itoh, Masayuki; Kosaka, Tatsuro; Maeda, Yoshitomo; Matsumoto, Hironori; Miyazawa, Takuya; Mori, Hideyuki; Nagano, Hosei; Namba, Yoshiharu; Ogasaka, Yasushi; Ogi, Keiji; Okajima, Takashi; Sugita, Satoshi; Suzuki, Yoshio; Tamura, Keisuke; Tawara, Yuzuru; Uesugi, Kentaro; Yamashita, Koujun; Yamauchi, Shigeo

    2012-09-01

    ASTRO-H is an international X-ray mission of ISAS/JAXA, which will be launched in 2014. One of the main characteristics of ASTRO-H is imaging spectroscopy in the hard X-ray band above 10 keV. ASTRO-H will carry two identical Hard X-ray telescopes (HXTs), whose mirror surfaces are coated with Pt/C depth-graded multilayers to enhance hard X-ray effective area up to 80 keV. HXT was designed based on the telescope on board the SUMIT balloon borne experiment. After feasibility study of the HXT design, the FM design has been deteremined. Mass production of the mirror shells at Nagoya University has been going on since August 2010, and production of mirror shells for HXT-1 was completed in March 2012. After the integation of X-ray mirrors for HXT-1, we measured hard X-ray performance of selected mirror shells for HXT-1 at a synchrotron radiation facility, SPring-8 beamline BL20B2. We will perform environment tests and ground calibarations at SPring-8 for HXT-1. In HXT-2, foil production is going on.

  5. Development of the ASTRO-H Soft X-ray Telescope (SXT): Engineering Model Performance

    NASA Technical Reports Server (NTRS)

    Okajima, Takashi; Serlemitsos, P. J.; Soong, Y.

    2011-01-01

    The X-ray astronomy satellite ASTRO-H, being developed under the collaboration among JAXA, NASA's GSFC and ESA, will have two Soft X-ray Telescopes (SXTs), among other instuments onboard, with a sensitive energy band below 12 keV. One is for an X-ray micorocalorimeter detector and the other for a X-ray CCD detector. The SXT uses a conically approximated Wolter I grazing incidence optic implemented by thin aluminum foil substrates with thickness of 0.152, 0.229, and 0.305 mm. It is similar to the Suzaku XRT, but with larger diameter (45 cm) and longer focal length (5.6 m). Goal of the angular resolution and effective area are 1 arcmin and 390 cm$A2$ at 6 keV, respectively. We made serveral improvements from Suzaku to ASTRO-H, such as thicker substrates, more forming mandrels, thinner epoxy layer for replication, stiffer housings, precise alignment bars, etc. With all these changes, we have fabricated the engineering test unit of the SXT. In this paper, we will discuss all the changes made, their effects, and report X-ray performance of the SXT test unit. An angular resolution of the test unit was measured at new Goddard X-ray calibration facility (100 m X-ray beamline) and was found to be 1.1 arcmin. We will also discuss further improvements toward the flight unit to be delivered to JAXA in 2012.

  6. Observations of the structure and evolution of solar flares with a soft X-ray telescope

    NASA Technical Reports Server (NTRS)

    Vorpahl, J. A.; Gibson, E. G.; Landecker, P. B.; Mckenzie, D. L.; Underwood, J. M.

    1975-01-01

    Soft X ray flare events were observed with the S-056 X-ray telescope that was part of the ATM complement of instruments aboard SKYLAB. Analyses of these data are reported. The observations are summarized and a detailed discussion of the X-ray flare structures is presented. The data indicated that soft X-ray emitted by a flare come primarily from an intense well-defined core surrounded by a region of fainter, more diffuse emission. An analysis of flare evolution indicates evidence for preliminary heating and energy release prior to the main phase of the flare. Core features are found to be remarkably stable and retain their shape throughout a flare. Most changes in the overall configuration seem to be result of the appearance, disappearance or change in brightness of individual features, rather than the restructuring or reorientation of these features. Brief comparisons with several theories are presented.

  7. Characterization and Evolution of the Swift X-ray Telescope Instrumental Background

    NASA Technical Reports Server (NTRS)

    Hill, Joanne; Pagani, C.; Morris, D. C.; Racusin, J.; Grupe, D.; Vetere, L.; Stroh, M.; Falcone, A.; Kennea, J.; Burrows, D. N.; Nousek, J. A.; Abbey, A. F.; Angelini, L.; Beardmore, A. P.; Campana, S.; Capalbi, M.; Chincarini, G.; Citterio O.; Cusumano, G.; Giommi, P.; Godet, O.; Hill, J. E.; LaParola, V.; Mangano, V.; Mineo, T.

    2007-01-01

    The X-ray telescope (XRT) on board the Swift Gamma Ray Burst Explorer has successfully operated since the spacecraft launch on 20 November 2004, automatically locating GRB afterglows, measuring their spectra and lightcurves and performing observations of high-energy sources. In this work we investigate the properties of the instrumental background, focusing on its dynamic behavior on both long and short timescales. The operational temperature of the CCD is the main factor that influences the XRT background level. After the failure of the Swift active on-board temperature control system, the XRT detector now operates at a temperature range between -75C and -45C thanks to a passive cooling Heat Rejection System. We report on the long-term effects on the background caused by radiation, consisting mainly of proton irradiation in Swift's low Earth orbit and on the short-term effects of transits through the South Atlantic Anomaly (SAA), which expose the detector to periods of intense proton flux. We have determined the fraction of the detector background that is due to the internal, instrumental background and the part that is due to unresolved astrophysical sources (the cosmic X-ray background) by investigating the degree of vignetting of the measured background and comparing it to the expected value from calibration data.

  8. Rocket studies of solar corona and transition region. [X-Ray spectrometer/spectrograph telescope

    NASA Technical Reports Server (NTRS)

    Acton, L. W.; Bruner, E. C., Jr.; Brown, W. A.; Nobles, R. A.

    1979-01-01

    The XSST (X-Ray Spectrometer/Spectrograph Telescope) rocket payload launched by a Nike Boosted Black Brant was designed to provide high spectral resolution coronal soft X-ray line information on a spectrographic plate, as well as time resolved photo-electric records of pre-selected lines and spectral regions. This spectral data is obtained from a 1 x 10 arc second solar region defined by the paraboloidal telescope of the XSST. The transition region camera provided full disc images in selected spectral intervals originating in lower temperature zones than the emitting regions accessible to the XSST. A H-alpha camera system allowed referencing the measurements to the chromospheric temperatures and altitudes. Payload flight and recovery information is provided along with X-ray photoelectric and UV flight data, transition camera results and a summary of the anomalies encountered. Instrument mechanical stability and spectrometer pointing direction are also examined.

  9. DynamiX, numerical tool for design of next-generation x-ray telescopes.

    PubMed

    Chauvin, Maxime; Roques, Jean-Pierre

    2010-07-20

    We present a new code aimed at the simulation of grazing-incidence x-ray telescopes subject to deformations and demonstrate its ability with two test cases: the Simbol-X and the International X-ray Observatory (IXO) missions. The code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, accounting for the x-ray interactions and for the telescope motion and deformation. The simulation produces images and spectra for any telescope configuration using Wolter I mirrors and semiconductor detectors. This numerical tool allows us to study the telescope performance in terms of angular resolution, effective area, and detector efficiency, accounting for the telescope behavior. We have implemented an image reconstruction method based on the measurement of the detector drifts by an optical sensor metrology. Using an accurate metrology, this method allows us to recover the loss of angular resolution induced by the telescope instability. In the framework of the Simbol-X mission, this code was used to study the impacts of the parameters on the telescope performance. In this paper we present detailed performance analysis of Simbol-X, taking into account the satellite motions and the image reconstruction. To illustrate the versatility of the code, we present an additional performance analysis with a particular configuration of IXO.

  10. DynamiX, numerical tool for design of next-generation x-ray telescopes

    SciTech Connect

    Chauvin, Maxime; Roques, Jean-Pierre

    2010-07-20

    We present a new code aimed at the simulation of grazing-incidence x-ray telescopes subject to deformations and demonstrate its ability with two test cases: the Simbol-X and the International X-ray Observatory (IXO) missions. The code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, accounting for the x-ray interactions and for the telescope motion and deformation. The simulation produces images and spectra for any telescope configuration using Wolter I mirrors and semiconductor detectors. This numerical tool allows us to study the telescope performance in terms of angular resolution, effective area, and detector efficiency, accounting for the telescope behavior. We have implemented an image reconstruction method based on the measurement of the detector drifts by an optical sensor metrology. Using an accurate metrology, this method allows us to recover the loss of angular resolution induced by the telescope instability. In the framework of the Simbol-X mission, this code was used to study the impacts of the parameters on the telescope performance. In this paper we present detailed performance analysis of Simbol-X, taking into account the satellite motions and the image reconstruction. To illustrate the versatility of the code, we present an additional performance analysis with a particular configuration of IXO.

  11. Telescope Scientist on the Advanced X-ray Astrophysics Observatory

    NASA Technical Reports Server (NTRS)

    VanSpeybroeck, L.; Smith, Carl M. (Technical Monitor)

    2002-01-01

    This period included many scientific observations made with the Chandra Observatory. The results, as is well known, are spectacular. Fortunately, the High Resolution Mirror Assembly (HRMA) performance continues to be essentially identical to that predicted from ground calibration data. The Telescope Scientist Team has improved the mirror model to provide a more accurate description to the Chandra observers and enable them to reduce the systematic errors and uncertainties in their data reduction. We also have made considerable progress in improving the scattering model. There also has been progress in the scientific program. At this time 58 distant clusters of galaxies have been observed. We are performing a systematic analysis of this rather large data set for the purpose of determining absolute distances utilizing the Sunyaev Zel'dovich effect. These observations also have been used to study the evolution of the cluster baryon mass function and the cosmological constraints which result from this evolution.

  12. Telescope Scientist on the Advanced X-Ray Astrophysics Observatory

    NASA Technical Reports Server (NTRS)

    VanSpeybroeck, L.; Smith, Carl M. (Technical Monitor)

    2002-01-01

    This period included many scientific observations made with the Chandra Observatory. The results, as is well known, are spectacular. Fortunately, the HRMA performance continues to be essentially identical to that predicted from ground calibration data. The Telescope Scientist Team has improved the mirror model to provide a more accurate description to the Chandra observers and enable them to reduce the systematic errors and uncertainties in their data reduction. There also has been progress in the scientific program. At this time 47 distant clusters of galaxies have been observed. We are performing a systematic analysis of this rather large data set for the purpose of determining absolute distances utilizing the Sunyaev Zel'dovich effect.

  13. Development of High Resolution Hard X-Ray Telescope with Multi-Layer Coatings

    NASA Technical Reports Server (NTRS)

    Gorenstein, Paul; Brinton, John C. (Technical Monitor)

    2005-01-01

    This is the annual report for the third year of a three-year program. Previous annual reports have described progress achieved in the first and second years. The major objective of this program is the development of a focusing hard X-ray telescope with moderately high angular resolution, i.e. comparable to the telescopes of XMM-Newton. The key ingredients of the telescope are a depth graded multilayer coatings and electroformed nickel substrates that are considerably lighter weight than those of previous missions such as XMM-Newton, which have had conventional single metal layer reflective coatings and have operated at much lower energy X-rays. The ultimate target mission for this technology is the Hard X-Ray Telescope (HXT) of the Constellation X-Ray Mission. However, it is applicable to potential SMEX and MIDEX programs as well. We are building upon technology that has proven to be successful in the XMM-Newton and SWIFT missions. The improvements that we are adding are a significant reduction in mass without much loss of angular resolution and an order of magnitude extension of the bandwidth through the use of multilayer coatings. The distinctive feature of this approach compared to those of other hard X-ray telescope programs is that we expect the angular resolution to be superior than telescopes made by other methods thanks to the structural integrity of the substrates. They are thin walled complete cylinders of revolution with a Wolter Type 1 figure; the front half is a parabola, the rear half a hyperbola.

  14. Design Parameters of Paraboloid-Hyperboloid Telescopes for X-ray Astronomy.

    PubMed

    Vanspeybroeck, L P; Chase, R C

    1972-02-01

    We have evaluated the principal optical characteristics of paraboloid-hyperboloid x-ray telescopes by a ray-tracing procedure; we find that our results for resolution, focal plane curvature, and finite source distance effects may be approximated in terms of the design parameters by simple empirical formulas.

  15. The structure of the coronal soft X-ray source associated with the dark filament disappearance of 1991 September 28 using the Yohkoh Soft X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Mcallister, Alan; Uchida, Yutaka; Tsuneta, Saku; Strong, Keith T.; Acton, Loren W.; Hiei, Eijiro; Bruner, Marilyn E.; Watanabe, Takashi; Shibata, Kazunari

    1992-01-01

    The structure of the coronal soft X-ray source associated with the dark filament disappearance on September 28, 1991, observed with the Soft X-ray Telescope, is examined as a possible example of the 'eruption-reconnection' model of filament disappearance. The results suggest, however, that this model may not fit. There is a strong possibility that much of the dark filament mass remains in the heated unwinding axial field.

  16. SuperHERO: Design of a New Hard X-Ray Focusing Telescope

    NASA Technical Reports Server (NTRS)

    Gaskin, Jessica; Elsner, Ronald; Ramsey, Brian; Wilson-Hodge, Colleen; Tennant, Allyn; Christe, Steven; Shih, Albert; Kiranmayee, Kilaru; Swartz, Douglas; Seller, Paul; Wilson, Matthew; Stuchlik, David; Weddendorf, Bruce

    2015-01-01

    SuperHERO is a hard x-ray (20-75 keV) balloon-borne telescope, currently in its proposal phase, that will utilize high angular-resolution grazing-incidence optics, coupled to novel CdTe multi-pixel, fine-pitch (250 micrometers) detectors. The high-resolution electroformed-nickel, grazing-incidence optics were developed at MSFC, and the detectors were developed at the Rutherford Appleton Laboratory in the UK, and are being readied for flight at GSFC. SuperHERO will use two active pointing systems; one for carrying out astronomical observations and another for solar observations during the same flight. The telescope will reside on a light-weight, carbon-composite structure that will integrate the Wallops Arc Second Pointer into its frame, for arcsecond or better pointing. This configuration will allow for Long Duration Balloon flights that can last up to 4 weeks. This next generation design, which is based on the High Energy Replicated Optics (HERO) and HERO to Explore the Sun (HEROES) payloads, will be discussed, with emphasis on the core telescope components.

  17. Solar-B X-ray Telescope (XRT) Concept Study Report

    NASA Technical Reports Server (NTRS)

    Golub, Leon

    1999-01-01

    The X-ray observations from the Yohkoh SXT provided the greatest step forward in our understanding of the solar corona in nearly two decades. Expanding on the accomplishments of Yohkoh, we believe that the scientific objectives of the Solar-B mission are achieved with a significantly improved X-ray telescope (XRT) similar to the SXT. The Solar-B XRT will have twice the spatial resolution and a broader temperature response, while building on the knowledge gained from the successful Yohkoh mission. We present the scientific justification for this view, discuss the instrumental requirements that flow from the scientific objectives, and describe the instrumentation to meet these requirements. We then provide a detailed discussion of the design activities carried out during Phase A, noting the conclusions that were reached in terms of their implications for the detailed design activities which are now commencing. Details of the instrument that have changed as a result of the Phase A studied are specifically noted, and areas of concern going into Phase B are highlighted. XRT is a grazing-incidence (GI) modified Wolter I X-ray telescope, of 35cm inner diameter and 2.7m focal length. The 2048x2048 back-illuminated CCD (now an ISAS responsibility) has 13.5 micron pixels, corresponding to 1.0 arcsec and giving full Sun field of view. This will be the highest resolution GI X-ray telescope ever flown for Solar coronal studies, and it has been designed specifically to observe both the high and low temperature coronal plasma. A small optical telescope provides visible light images for co-alignment with the Solar-B optical and EUV instruments. The XRT science team is working in close cooperation with our Japanese colleagues in the design and construction of this instrument. All of the expertise and resources of the High Energy and Solar/Stellar Divisions of the Center for Astrophysics are being made available to this program, and our team will carry its full share of

  18. Optical studies of X-ray peculiar chromosphereically active stars

    NASA Astrophysics Data System (ADS)

    Pandey, J. C.

    2006-02-01

    A multiwavelength study of the late-type active stars, selected on the basis of their X-ray and radio luminosities is presented in this thesis. For FR Cnc, a photometric period 0.8267 +/- 0.0004 d has been established. The strong variation in the phase and amplitude of the FR Cnc light curves when folded on this period implies the presence of evolving and migrating spots or spot groups on its surface. A photometric period of 18.802 +/- 0.074 has been discovered in the star HD 81032. The shape and amplitude of the photometric light curves of FR Cnc, HD 81032, HD 95559 and LO Peg are observed to be changing from one epoch to another. The change in the amplitude is mainly due to a change in the minimum of the light curve, and this May be due to a change in the spot coverage. This indicates that photometric variability is due to the presence of dark spots on the surface of active star. Two groups of spots are identified for FR Cnc and LO Peg. The spots are found to migrate, and migration periods of 0.97 year and 0.93 year are determined from the 4 years of data. A migration period of 1.12 years for one group of spots in LO Peg is also determined. Formation of a new group of spots in the star HD 95559 was also seen during our observations. A single large group of spots is found to migrate, and a migration period of 7.32 +/- 0.04 years is determined for HD 81032. The stars FR Cnc, HD 81032, HD 160934 and LO Peg are seen to be redder at the light minimum and we interpret this is due to the relatively cooler temperature of the darker regions present in the visible hemisphere. We find the lack of color-brightness correlation in the star HD 95559 and this May be due to the presence of bright faculae and plages like regions accompanied by dark spots in any one component of the this binary system. The optical spectroscopy of FR Cnc and HD 81032 carried out during 2002-2003, reveals the presence of strong and variable Ca II H and K, Halpha and Hbeta emission features indicative

  19. The Imaging Properties of a Silicon Wafer X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Joy, M. K.; Kolodziejczak, J. J.; Weisskopf, M. C.; Fair, S.; Ramsey, B. D.

    1994-01-01

    Silicon wafers have excellent optical properties --- low microroughness and good medium-scale flatness --- which Make them suitable candidates for inexpensive flat-plate grazing-incidence x-ray mirrors. On short spatial scales (less than 3 mm) the surface quality of silicon wafers rivals that expected of the Advanced X-Ray Astrophysics Facility (AXAF) high-resolution optics. On larger spatial scales, however, performance may be degraded by the departure from flatness of the wafer and by distortions induced by the mounting scheme. In order to investigate such effects, we designed and constructed a prototype silicon-wafer x-ray telescope. The device was then tested in both visible light and x rays. The telescope module consists of 94 150-mm-diameter wafers, densely packed into the first stage of a Kirkpatrick-Baez configuration. X-ray tests at three energies (4.5, 6.4, and 8.0 keV) showed an energy-independent line spread function with full width at half maximum (FWHM) of 150 arcseconds, dominated by deviations from large-scale flatness.

  20. Testing multilayer-coated polarizing mirrors for the LAMP soft X-ray telescope

    NASA Astrophysics Data System (ADS)

    Spiga, D.; Salmaso, B.; She, R.; Tayabaly, K.; Wen, M.; Banham, R.; Costa, E.; Feng, H.; Giglia, A.; Huang, Q.; Muleri, F.; Pareschi, G.; Soffitta, P.; Tagliaferri, G.; Valsecchi, G.; Wang, Z.

    2015-09-01

    The LAMP (Lightweight Asymmetry and Magnetism Probe) X-ray telescope is a mission concept to measure the polarization of X-ray astronomical sources at 250 eV via imaging mirrors that reflect at incidence angles near the polarization angle, i.e., 45 deg. Hence, it will require the adoption of multilayer coatings with a few nanometers dspacing in order to enhance the reflectivity. The nickel electroforming technology has already been successfully used to fabricate the high angular resolution imaging mirrors of the X-ray telescopes SAX, XMM-Newton, and Swift/XRT. We are investigating this consolidated technology as a possible technique to manufacture focusing mirrors for LAMP. Although the very good reflectivity performances of this kind of mirrors were already demonstrated in grazing incidence, the reflectivity and the scattering properties have not been tested directly at the unusually large angle of 45 deg. Other possible substrates are represented by thin glass foils or silicon wafers. In this paper we present the results of the X-ray reflectivity campaign performed at the BEAR beamline of Elettra - Sincrotrone Trieste on multilayer coatings of various composition (Cr/C, Co/C), deposited with different sputtering parameters on nickel, silicon, and glass substrates, using polarized X-rays in the spectral range 240 - 290 eV.

  1. Composite Image of the Cat's Eye From Chandra X-Ray Observatory and Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Left image: The x-ray data from the Chandra X-Ray Observatory (CXO) has revealed a bright central star surrounded by a cloud of multimillion-degree gas in the planetary nebula known as the Cat's Eye. This CXO image, where the intensity of the x-ray emission is correlated to the brightness of the orange coloring, captures the expulsion of material from a star that is expected to collapse into a white dwarf in a few million years. The intensity of x-rays from the central star was unexpected, and it is the first time astronomers have seen such x-ray emission from the central star of a planetary nebula. Right image: An image of Cat's Eye taken by the Hubble Space Telescope (HST). By comparing the CXO data with that from the HST, researchers are able to see where the hotter, x-ray emitting gas appears in relation to the cooler material seen in optical wavelengths by the HST. The CXO team found that the chemical abundance in the region of hot gas (its x-ray intensity is shown in purple) was not like those in the wind from the central star and different from the outer cooler material (the red and green structures.) Although still incredibly energetic and hot enough to radiate x-rays, CXO shows the hot gas to be somewhat cooler than scientists would have expected for such a system. CXO image credit: (NASA/UIUC/Y. Chu et al.) HST image credit: (NASA/HST)

  2. A Preliminary Research on the Development of the Hard X-ray Imaging Telescope

    NASA Astrophysics Data System (ADS)

    Zheng, Chun-Xiao; Cai, Ming-Sheng; Hu, Yi-Ming; Huang, Yong-Yi; Gong, Yi-Zhong

    2014-10-01

    The hard X-ray imaging telescope based on the Fourier transform imaging technique is introduced. The double-layer parallel gratings are used to make the modulation and coding on the light emerging from a celestial X-ray source, the modulated light is acquired, to make the optoelectronic conversion by scintillation crystal detectors, and finally read out by the electronic system. The modulation collimator X-ray telescopes can be divided into two types: the spatial modulation and temporal modulation. The temporal modulation system requires the scanning motion of the detector system, but the spatial modulation system requires no motion. The technology of grating fabrication is investigated, and the basic structure design of the collimators is given. The principal compo- nents of the prototype hard X-ray imaging telescope of spatial modulation type are successfully developed, including the 8 CsI crystal detector modules (contain- ing photomultipliers or PMTs), 8-channel shaping amplifiers (two of them are prepared for experiments), and the data acquisition system. And the preliminary test results of the electronic system are also given.

  3. Design of the pre-collimator for the NeXT x-ray telescopes

    NASA Astrophysics Data System (ADS)

    Mori, Hideyuki; Ogasaka, Yasushi; Ishida, Manabu; Maeda, Yoshitomo; Tamura, Keisuke; Kunieda, Hideyo; Furuzawa, Akihiro; Haba, Yoshito; Miyazawa, Takuya; Yamashita, Koujun; Awaki, Hisamitsu; Serlemitsos, Peter J.; Soong, Yang; Chan, Kai-Wing; Okajima, Takashi

    2008-07-01

    We present the design of the pre-collimator for the X-ray telescopes (XRTs) onboard New X-ray Telescope (NeXT). The optical design adopted for the NeXT XRTs is conically-approximated Wolter-I type optics. The tightly-nested reflectors with thin substrates (150-300 μm) enable us to achieve the large effective area and extremely light weight simultaneously. However, due to the packed reflector shells, X-rays from the outside of the XRT field of view occasionally arrive at the focal plane without the normal double reflection (stray lights), and then produce a ghost image on the detector. Thus, the stray-lights contamination degrades sensitivity of the source detection In order to reduce the stray lights efficiently, we plan to mount a collimator onto each telescope (referred to as pre-collimator), which is similar to that equipped with the Suzaku XRTs. The pre-collimator consists of coaxially-nested cylindrical blades, each of which is aligned radially with the corresponding primary refector. We found the height of the pre-collimator blade to be ~100 mm that is required to block the X-rays with off-axis angles of 30'-50', which are the main ligth pass of the stray lights for the NeXT XRTs.

  4. Aberrations in square pore micro-channel optics used for x-ray lobster eye telescopes

    NASA Astrophysics Data System (ADS)

    Willingale, R.; Pearson, J. F.; Martindale, A.; Feldman, C. H.; Fairbend, R.; Schyns, E.; Petit, S.; Osborne, J. P.; O'Brien, P. T.

    2016-07-01

    We identify all the significant aberrations that limit the performance of square pore micro-channel plate optics (MPOs) used as an X-ray lobster eye. These include aberrations intrinsic to the geometry, intrinsic errors associated with the slumping process used to introduce a spherical form to the plates and imperfections associated with the plate manufacturing process. The aberrations are incorporated into a comprehensive software model of the X-ray response of the optics and the predicted imaging response is compared with the measured X-ray performance obtained from a breadboard lobster eye. The results reveal the manufacturing tolerances which limit the current performance of MPOs and enable us to identify particular intrinsic aberrations which will limit the ultimate performance we can expect from MPO-lobster eye telescopes.

  5. Evaluation of a ''CMOS'' Imager for Shadow Mask Hard X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Desai, Upendra D.; Orwig, Larry E.; Oergerle, William R. (Technical Monitor)

    2002-01-01

    We have developed a hard x-ray coder that provides high angular resolution imaging capability using a coarse position sensitive image plane detector. The coder consists of two Fresnel zone plates. (FZP) Two such 'FZP's generate Moire fringe patterns whose frequency and orientation define the arrival direction of a beam with respect to telescope axis. The image plane detector needs to resolve the Moire fringe pattern. Pixilated detectors can be used as an image plane detector. The recently available 'CMOS' imager could provide a very low power large area image plane detector for hard x-rays. We have looked into a unit made by Rad-Icon Imaging Corp. The Shadow-Box 1024 x-ray camera is a high resolution 1024xl024 pixel detector of 50x50 mm area. It is a very low power, stand alone camera. We present some preliminary results of our investigation of evaluation of such camera.

  6. Grazing incidence telescopes - A new class for soft X-ray and EUV spectroscopy

    NASA Technical Reports Server (NTRS)

    Hettrick, M. C.; Bowyer, S.

    1984-01-01

    A new class of grazing incidence telescopes is identified, and its advantages for stellar spectroscopy are discussed. In particular, three types of telescope geometry consisting of a primary and a secondary, both at grazing incidence, are proposed. Type I delivers a converging beam having a real focus; type II delivers a diverging beam from a virtual focus, and type III delivers a collimated beam concentrated relative to the primary aperture. The three telescope types are shown to possess unique properties which improve the efficiency and shorten the length of soft X-ray/EUV spectrographs.

  7. Use of graphite epoxy composites in the Solar-A Soft X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Jurcevich, B. K.; Bruner, M. E.

    1990-01-01

    This paper describes the use of composite materials in the Soft X-Ray Telescope (SXT). One of the primary structural members of the telescope is a graphite epoxy metering tube. The metering tube maintains the structural stability of the telescope during launch as well as the focal length through various environmental conditions. The graphite epoxy metering tube is designed to have a negative coefficient of thermal expansion to compensate for the positive expansion of titanium structural supports. The focus is maintained to + or - 0.001 inch by matching the CTE of the composite tube to the remaining structural elements.

  8. Performance of ASTRO-H hard x-ray telescope (HXT)

    NASA Astrophysics Data System (ADS)

    Awaki, Hisamitsu; Kunieda, Hideyo; Ishida, Manabu; Matsumoto, Hironori; Furuzawa, Akihiro; Haba, Yoshito; Hayashi, Takayuki; Iizuka, Ryo; Ishibashi, Kazunori; Itoh, Masayuki; Kosaka, Tatsuro; Maeda, Yoshitomo; Mitsuishi, Ikuyuki; Miyazawa, Takuya; Mori, Hideyuki; Nagano, Hosei; Namba, Yoshiharu; Ogasaka, Yasushi; Ogi, Keiji; Okajima, Takashi; Sugita, Satoshi; Suzuki, Yoshio; Tamura, Keisuke; Tawara, Yuzuru; Uesugi, Kentaro; Yamauchi, Shigeo

    2016-07-01

    The Japanese X-ray Astronomy Satellite, Hitomi (ASTRO-H) carries hard X-ray imaging system, covering the energy band from 5 keV to 80 keV. The hard X-ray imaging system consists of two hard X-ray telescopes (HXT) and the focal plane detectors (HXI). The HXT employs tightly-nested, conically-approximated thin foil Wolter-I optics. The mirror surfaces of HXT were coated with Pt/C depth-graded multilayers. We carried out ground calibrations of HXTs at the synchrotron radiation facility SPring-8/ BL20B2 Japan, and found that total effective area of two HXTs was about 350 cm2 at 30 keV, and the half power diameter of HXT was about 1.'9. After the launch of Hitomi, Hitomi observed several targets during the initial functional verification of the onboard instruments. The Hitomi software and calibration team (SCT) provided the Hitomi's data of G21.5-0.9, a pulsar wind nebula, to the hardware team for the purpose of the instrument calibration. Through the analysis of the in-flight data, we have confirmed that the X-ray performance of HXTs in orbit was consistent with that obtained by the ground calibrations.

  9. Mass and Energy of Erupting Solar Plasma Observed with the X-Ray Telescope on Hinode

    NASA Astrophysics Data System (ADS)

    Lee, Jin-Yi; Raymond, John C.; Reeves, Katharine K.; Moon, Yong-Jae; Kim, Kap-Sung

    2015-01-01

    We investigate seven eruptive plasma observations by Hinode/XRT. Their corresponding EUV and/or white light coronal mass ejection features are visible in some events. Five events are observed in several passbands in X-rays, which allows for the determination of the eruptive plasma temperature using a filter ratio method. We find that the isothermal temperatures vary from 1.6 to 10 MK. These temperatures are an average weighted toward higher temperature plasma. We determine the mass constraints of eruptive plasmas by assuming simplified geometrical structures of the plasma with isothermal plasma temperatures. This method provides an upper limit to the masses of the observed eruptive plasmas in X-ray passbands since any clumping causes the overestimation of the mass. For the other two events, we assume the temperatures are at the maximum temperature of the X-ray Telescope (XRT) temperature response function, which gives a lower limit of the masses. We find that the masses in XRT, ~3 × 1013-5 × 1014 g, are smaller in their upper limit than the total masses obtained by LASCO, ~1 × 1015 g. In addition, we estimate the radiative loss, thermal conduction, thermal, and kinetic energies of the eruptive plasma in X-rays. For four events, we find that the thermal conduction timescales are much shorter than the duration of eruption. This result implies that additional heating during the eruption may be required to explain the plasma observations in X-rays for the four events.

  10. Progress on indirect glass slumping for future x-ray telescope optics

    NASA Astrophysics Data System (ADS)

    Winter, Anita; Breunig, Elias; Friedrich, Peter; Proserpio, Laura

    2014-07-01

    Large X-ray telescopes for future observations need to combine a big collecting area with good angular resolution. Due to the mass limits of the launching rocket, light-weight materials are needed in order to enhance the collecting area in future telescopes. We study the development of mirror segments made from thin glass sheets which are shaped by thermal slumping. At MPE we follow the indirect approach which enables us the production of the parabolic and hyperbolic part of the Wolter type I mirrors in one piece. In our recent research we have used a test mould made of CeSiC™ for slumping processes in our lab furnace as well as in a heatable vacuum chamber, to avoid oxidation and air enclosure. Additional slumping tests in the vacuum furnace have been carried out using a Kovar mould and are compared with results under air. We describe the experimental set-up, the slumping process and the metrology methods and give an outlook on future activities.

  11. The nuclear spectroscopic telescope array (NuSTAR) high-energy X-ray mission

    NASA Astrophysics Data System (ADS)

    Madsen, Kristin K.; Harrison, Fiona A.; An, Hongjun; Boggs, Steven E.; Christensen, Finn E.; Cook, Rick; Craig, William W.; Forster, Karl; Fuerst, Felix; Grefenstette, Brian; Hailey, Charles J.; Kitaguchi, Takao; Markwardt, Craig; Mao, Peter; Miyasaka, Hiromasa; Rana, Vikram R.; Stern, Daniel K.; Zhang, William W.; Zoglauer, Andreas; Walton, Dominic; Westergaard, Niels J.

    2014-07-01

    The Nuclear Spectroscopic Telescope Array (NuSTAR) mission was launched on 2012 June 13 and is the first focusing high-energy X-ray telescope in orbit operating above ~10 keV. NuSTAR flies two co-aligned Wolter-I conical approximation X-ray optics, coated with Pt/C and W/Si multilayers, and combined with a focal length of 10.14 meters this enables operation from 3-79 keV. The optics focus onto two focal plane arrays, each consisting of 4 CdZnTe pixel detectors, for a field of view of 12.5 arcminutes. The inherently low background associated with concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with a more than 100-fold improvement in sensitivity, and with an effective point spread function FWHM of 18 arcseconds (HPD ~1), NuSTAR provides a leap of improvement in resolution over the collimated or coded mask instruments that have operated in this bandpass. We present in-orbit performance details of the observatory and highlight important science results from the first two years of the mission.

  12. A Normal Incidence X-ray Telescope (NIXT) Sounding Rocket Payload

    NASA Technical Reports Server (NTRS)

    Golub, Leon

    1996-01-01

    During the past year the changeover from the normal incidence X ray telescope (NIXT) program to the new TXI sounding rocket program was completed. The NIXT effort, aimed at evaluating the viability of the remaining portions of the NIXT hardware and design has been finished and the portions of the NIXT which are viable and flightworthy, such as filters, mirror mounting hardware, electronic and telemetry interface systems, are now part of the new rocket payload. The backup NIXT multilayer-coated X ray telescope and its mounting hardware have been completely fabricated and are being stored for possible future use in the TXI rocket. The h-alpha camera design is being utilized in the TXI program for real-time pointing verification and control via telemetry. Two papers, summarizing scientific results from the NIXT rocket program were published this year.

  13. Multi-Spectral Solar Telescope Array. II - Soft X-ray/EUV reflectivity of the multilayer mirrors

    NASA Technical Reports Server (NTRS)

    Barbee, Troy W., Jr.; Weed, J. W.; Hoover, Richard B.; Allen, Maxwell J.; Lindblom, Joakim F.; O'Neal, Ray H.; Kankelborg, Charles C.; Deforest, Craig E.; Paris, Elizabeth S.; Walker, Arthur B. C., Jr.

    1991-01-01

    The Multispectral Solar Telescope Array is a rocket-borne observatory which encompasses seven compact soft X-ray/EUV, multilayer-coated, and two compact far-UV, interference film-coated, Cassegrain and Ritchey-Chretien telescopes. Extensive measurements are presented on the efficiency and spectral bandpass of the X-ray/EUV telescopes. Attention is given to systematic errors and measurement errors.

  14. Observations of the quiet Sun from the soft x ray telescope on Yohkoh

    NASA Technical Reports Server (NTRS)

    Strong, Keith T.

    1992-01-01

    The Soft X-ray Telescope (SXT) on Yohkoh has obtained many thousands of images suitable for studying the quiet Sun. It will give a new perspective on the types of structures, their frequency of occurrence, and their lifetimes that will provide an invaluable tool for planning SOHO (Solar and Heliospheric Observatory) observations of the solar corona. The range of corona phenomena and the dynamic nature of the quiet Sun are illustrated.

  15. A Future Generation High Angular Resolution X-ray Telescope Based Upon Physical Optics

    NASA Astrophysics Data System (ADS)

    Gorenstein, Paul

    2013-04-01

    Although the highest priority objective for the next major X-ray mission is high resolution spectroscopy we will ultimately want the next generation high angular resolution X-ray observatory. This author believes that the 0.5 arc second angular resolution of the Chandra X-Ray Observatory is likely to be close to the best that can be obtained with grazing incidence optics, especially with larger effective area. Telescopes based upon physical optics, diffraction and refraction that transmit rather than reflect X-rays can have an angular resolution of a mili arc second or better. Combining the diffractive and refractive components into one unit can neutralize the chromatic aberration of each individually over a ~15% bandwidth at 6 keV. The aperture could be divided into several diffractive-refractive pairs to broaden the bandwidth. Furthermore these telescopes would be very low cost, very light weight, and more tolerant of figure errors and surface roughness than grazing incidence telescopes. However, focal lengths are of the order of 1000 km, which requires a new mission architecture consisting of long distance formation-flying between two spacecraft, one hosting the optics, the other, the detector. One of the spacecraft requires propulsion, provided by, for example, ion engines to maintain the optics-detector alignment by counteracting gravity gradient forces, and for changing targets. Although their effective area can be large and their angular resolution very high diffractive-refractive telescopes are not necessarily more sensitive than Chandra because their large focal plane scale (1 mili arc second ~ 1 mm) subjects them to a higher level of cosmic ray background and their opacity results in a lower energy limit of 2 keV. The intrinsic field of view is wide but the large focal length scale and practical limits on the size of the detector array results in a small field of view.

  16. Localization algorithms for micro-channel x-ray telescope on board SVOM space mission

    NASA Astrophysics Data System (ADS)

    Gosset, L.; Götz, D.; Osborne, J.; Willingale, R.

    2016-07-01

    SVOM is a French-Chinese space mission to be launched in 2021, whose goal is the study of Gamma-Ray Bursts, the most powerful stellar explosions in the Universe. The Micro-channel X-ray Telescope (MXT) is an X-ray focusing telescope, on board SVOM, with a field of view of 1 degree (working in the 0.2-10 keV energy band), dedicated to the rapid follow-up of the Gamma-Ray Bursts counterparts and to their precise localization (smaller than 2 arc minutes). In order to reduce the optics mass and to have an angular resolution of few arc minutes, a "lobster-Eye" configuration has been chosen. Using a numerical model of the MXT Point Spread Function (PSF) we simulated MXT observations of point sources in order to develop and test different localization algorithms to be implemented on board MXT. We included preliminary estimations of the instrumental and sky background. The algorithms on board have to be a combination of speed and precision (the brightest sources are expected to be localized at a precision better than 10 arc seconds in the MXT reference frame). We present the comparison between different methods such as barycentre, PSF fitting in one or two dimensions. The temporal performance of the algorithms is being tested using the X-ray afterglow data base of the XRT telescope on board the NASA Swift satellite.

  17. SuperHERO: The Next Generation Hard X-Ray HEROES Telescope

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.; Gaskin, Jessica A.; Christe, Steven D.; Elsner, Ronald F.; Ramsey, Brian D.; Seller, Paul; Shih, Albert Y.; Stuchlik, David W.; Swartz, Douglas A.; Tenant, Allyn F.; Wilson, Matthew D.

    2014-01-01

    SuperHERO is a new high-sensitivity Long Duration Balloon (LDB)-capable, hard-x-ray (20-75 keV) telescope for making novel astrophysics and heliophysics observations. The proposed SuperHERO payload will be developed jointly by the Astrophysics Office at NASA Marshall Space Flight Center, the Solar Physics Laboratory and Wallops Flight Facility at NASA Goddard Space Flight Center. SuperHERO is a follow-on payload to the High Energy Replicated Optics to Explore the Sun (HEROES) balloon-borne telescope that recently launched from Fort Sumner, NM in September of 2013. The HEROES core instrument is a hard x-ray telescope consisting of x-ray 109 optics configured into 8 modules. Each module is aligned to a matching gas-filled detector at a focal length of 6 m. SuperHERO will make significant improvements to the HEROES payload, including: new solid-state multi-pixel CdTe detectors, additional optics, the Wallops Arc-Second Pointer, alignment monitoring systems and lighter gondola.

  18. SuperHERO: The Next Generation Hard X-ray HEROES Telescope

    NASA Technical Reports Server (NTRS)

    Gaskin, Jessica A.; Christe, Steven D.; Wilson-Hodge, Colleen; Shih, Albert Y. M.; Ramsey, Brian D.; Tennant, Allyn F.; Swartz, Douglas A.

    2014-01-01

    SuperHERO is a new high-sensitivity Long Duration Balloon (LDB)-capable, hard-x-ray (20-75 keV) telescope for making novel astrophysics and heliophysics observations. The proposed SuperHERO payload will be developed jointly by the Astrophysics Office at NASA Marshall Space Flight Center, the Solar Physics Laboratory and Wallops Flight Facility at NASA Goddard Space Flight Center. SuperHERO is a follow-on payload to the High Energy Replicated Optics to Explore the Sun (HEROES) balloon-borne telescope that recently launched from Fort Sumner, NM in September of 2013. The HEROES core instrument is a hard x-ray telescope consisting of x-ray 109 optics configured into 8 modules. Each module is aligned to a matching gas-filled detector at a focal length of 6 m. SuperHERO will make significant improvements to the HEROES payload, including: new solid-state multi-pixel CdTe detectors, additional optics, the Wallops Arc-Second Pointer, alignment monitoring systems and lighter gondola.

  19. X-ray telescope onboard Astro-E: optical design and fabrication of thin foil mirrors.

    PubMed

    Kunieda, H; Ishida, M; Endo, T; Hidaka, Y; Honda, H; Imamura, K; Ishida, J; Maeda, M; Misaki, K; Shibata, R; Furuzawa, A; Haga, K; Ogasaka, Y; Okajima, T; Tawara, Y; Terashima, Y; Watanabe, M; Yamashita, K; Yoshioka, T; Serlemitsos, P J; Soong, Y; Chan, K W

    2001-02-01

    X-ray telescopes (XRT's) of nested thin foil mirrors are developed for Astro-E, the fifth Japanese x-ray astronomy satellite. Although the launch was not successful, the design concept, fabrication, and alignment procedure are summarized. The main purpose of the Astro-E XRT is to collect hard x rays up to 10 keV with high efficiency and to provide medium spatial resolution in limited weight and volume. Compared with the previous mission, Advanced Satellite for Cosmology and Astrophysics (ASCA), a slightly longer focal length of 4.5-4.75 m and a larger diameter of 40 cm yields an effective area of 1750 cm2 at 8 keV with five telescopes. The image quality is also improved to 2-arc min half-power diameter by introduction of a replication process. Platinum is used instead of gold for the reflectors of one of the five telescopes to enhance the high-energy response. The fabrication and alignment procedure is also summarized. Several methods for improvement are suggested for the reflight Astro-E II mission and for other future missions. Preflight calibration results will be described in a forthcoming second paper, and a detailed study of images will be presented in a third paper.

  20. X-ray polarimetry with the Polarization Spectroscopic Telescope Array (PolSTAR)

    NASA Astrophysics Data System (ADS)

    Krawczynski, Henric S.; Stern, Daniel; Harrison, Fiona A.; Kislat, Fabian F.; Zajczyk, Anna; Beilicke, Matthias; Hoormann, Janie; Guo, Qingzhen; Endsley, Ryan; Ingram, Adam R.; Miyasaka, Hiromasa; Madsen, Kristin K.; Aaron, Kim M.; Amini, Rashied; Baring, Matthew G.; Beheshtipour, Banafsheh; Bodaghee, Arash; Booth, Jeffrey; Borden, Chester; Böttcher, Markus; Christensen, Finn E.; Coppi, Paolo S.; Cowsik, Ramanath; Davis, Shane; Dexter, Jason; Done, Chris; Dominguez, Luis A.; Ellison, Don; English, Robin J.; Fabian, Andrew C.; Falcone, Abe; Favretto, Jeffrey A.; Fernández, Rodrigo; Giommi, Paolo; Grefenstette, Brian W.; Kara, Erin; Lee, Chung H.; Lyutikov, Maxim; Maccarone, Thomas; Matsumoto, Hironori; McKinney, Jonathan; Mihara, Tatehiro; Miller, Jon M.; Narayan, Ramesh; Natalucci, Lorenzo; Özel, Feryal; Pivovaroff, Michael J.; Pravdo, Steven; Psaltis, Dimitrios; Okajima, Takashi; Toma, Kenji; Zhang, William W.

    2016-02-01

    This paper describes the Polarization Spectroscopic Telescope Array (PolSTAR), a mission proposed to NASA's 2014 Small Explorer (SMEX) announcement of opportunity. PolSTAR measures the linear polarization of 3-50 keV (requirement; goal: 2.5-70 keV) X-rays probing the behavior of matter, radiation and the very fabric of spacetime under the extreme conditions close to the event horizons of black holes, as well as in and around magnetars and neutron stars. The PolSTAR design is based on the technology developed for the Nuclear Spectroscopic Telescope Array (NuSTAR) mission launched in June 2012. In particular, it uses the same X-ray optics, extendable telescope boom, optical bench, and CdZnTe detectors as NuSTAR. The mission has the sensitivity to measure ˜1% linear polarization fractions for X-ray sources with fluxes down to ˜5 mCrab. This paper describes the PolSTAR design as well as the science drivers and the potential science return.

  1. An X-ray calibration facility with a dynamical pencil beam for the post-Astro-E2 telescopes

    NASA Astrophysics Data System (ADS)

    Maeda, Yoshitomo; Itoh, Akiharu; Itoh, Kei; Kunieda, Hideyo; Haba, Yoshito; Hayakawa, Akira; Iizuka, Ryo; Inoue, Chiaki; Ishida, Manabu; Misaki, Kazutami; Mori, Hideyuki; Shibata, Ryo

    2003-03-01

    We report a new calibration system for large size X-ray optics at ISAS. We adapted a 'dynamical' pencil beam collimated from an X-ray generator, the maximum voltage for which is 50 kV. By combining two stage systems for the X-ray generator and a collimator, the pencil beam dynamically sweeps across a circular region of a telescope with the radius of 60 cm at maximum. In this case, the X-ray telescope and the focal plane detector are both statically fixed. A 4.4~m long rail for detector stage and two positions of the telescope stage provide focal lengths from 4.5 to 12 m, while the previous system can accommodate 4.5 or 4.75 m focal length. The preliminary performance of this system is summarized in this paper. For the post-Astro-EII satellite, a hard X-ray multi-layer supermirror with an unprecedented sensitivity up to 80~keV is strongly expected. This beam facility is of importance because the hard X-ray mirrors always require a long focal length of 8-12 m due to the small reflection angle (about 0.3 degree). Focal length and diameter of future telescopes are always decided by the boundary conditions of the mission at the last moment of the design freeze. Our new X-ray beam facility is designed to match with any kind of X-ray telescope parameters.

  2. X-Ray Reprocessing in Active Galactic Nuclei

    NASA Technical Reports Server (NTRS)

    Begelman, Mitchell C.

    2004-01-01

    This is the final report for research entitled "X-ray reprocessing in active galactic nuclei," into X-ray absorption and emission in various classes of active galaxy via X-ray spectral signatures. The fundamental goal of the research was to use these signatures as probes of the central engine structure and circumnuclear environment of active galactic nuclei. The most important accomplishment supported by this grant involved the detailed analysis and interpretation of the XMM data for the bright Seyfert 1 galaxy MCG-6-30-15. This work was performed by Drs. Christopher Reynolds and Mitchell Begelman in collaboration with Dr. Jorn Wilms (University of Tubingen, Germany; PI of the XMM observation) and other European scientists. With XMM we obtained medium resolution X-ray spectra of unprecedented quality for this Seyfert galaxy. Modeling the X-ray spectrum within the framework of accretion disk reflection models produced the first evidence for energy extraction from the spin of a black hole. Specifically, we found that the extreme gravitational redshifts required to explain the X-ray spectrum suggests that the bulk of the energy dissipation is concentrated very close to the black hole, in contrast with the expectations of any pure accretion disk model. In a second paper we addressed the low- energy spectral complexity and used RXTE specta to pin down the high-energy spectral index, thus firming up our initial interpretation. Additionally, we carried out detailed spectral and variability analyses of a number of Seyfert and radio galaxies (e.g., NGC 5548 and 3C 111) and developed general techniques that will be useful in performing X-ray reverberation mapping of accretion disks in AGN, once adequate data becomes available. A list of papers supported by this research is included.

  3. Single-Grid-Pair Fourier Telescope for Imaging in Hard-X Rays and gamma Rays

    NASA Technical Reports Server (NTRS)

    Campbell, Jonathan

    2008-01-01

    This instrument, a proposed Fourier telescope for imaging in hard-x rays and gamma rays, would contain only one pair of grids made of an appropriate radiation-absorpting/ scattering material, in contradistinction to multiple pairs of such as grids in prior Fourier x- and gamma-ray telescopes. This instrument would also include a relatively coarse gridlike image detector appropriate to the radiant flux to be imaged. Notwithstanding the smaller number of grids and the relative coarseness of the imaging detector, the images produced by the proposed instrument would be of higher quality.

  4. Recent performance of the normal incident x-ray telescope with adaptive optics

    NASA Astrophysics Data System (ADS)

    Kitamoto, S.; Ishii, R.; Nukamori, S.; Imai, K.; Mochida, A.; Sato, S.; Ohgi, Y.; Yoshida, Y.; Hoshino, A.

    2016-09-01

    We report recent results of the performance measurement of our X-ray telescope with adaptive optics. The telescope is designed to use the 13.5nm EUV with the Mo/Si multilayers, making a normal incident optics. The primary mirror is 80mm in its diameter and the focal length of 2m. The deformable mirror is controlled by measuring a wave-front of an optical laser. Effects of a difference between the light paths from the reference and from an object are examined. The angular resolution is measured with optical light and we confirm almost diffraction limited resolution as well as its appropriate function as adaptive optics.

  5. Swift-X-Ray Telescope Monitoring of the Candidate Supergiant Fast X-ray Transient IGR J16418-4532

    NASA Technical Reports Server (NTRS)

    Romano, P.; Mangano, V.; Ducci, L.; Esposito, P.; Evans, P. A.; Vercellone, S.; Kennea, J. A.; Burrows, D. N.; Gehrels, N.

    2012-01-01

    We report on the Swift monitoring of the candidate supergiant fast X-ray transient (SFXT) IGR J16418-4532, for which both orbital and spin periods are known (approx. 3.7 d and approx.1250 s, respectively). Our observations, for a total of approx. 43 ks, span over three orbital periods and represent the most intense and complete sampling of the light curve of this source with a sensitive X-ray instrument. With this unique set of observations, we can address the nature of this transient. By applying the clumpy wind model for blue supergiants to the observed X-ray light curve, and assuming a circular orbit, the X-ray emission from this source can be explained in terms of the accretion from a spherically symmetric clumpy wind, composed of clumps with different masses, ranging from approx. 5 × 10(exp 16) to 10(exp 21) g. Our data suggest, based on the X-ray behaviour, that this is an intermediate SFXT.

  6. Calibration of the Soft X-ray Telescopes (SXT) Onboard the ASTRO-H Satellite

    NASA Technical Reports Server (NTRS)

    Soong, Yang; Okajima, Takashi; Serlemitsos, Peter J.

    2013-01-01

    ASTRO-H is an astrophysics satellite dedicated for non-dispersive X-ray spectroscopic study on selective celestial X-ray sources. Among the onboard instruments there are four Wolter-I X-ray mirrors of their reflectors' figure in conical approximation. Two of the four are soft X-ray mirrors, of which the energy range is from a few hundred eV to 15 keV. The focal point instruments will be a calorimeter (SXS) and a CCD camera (SXI), respectively. The mirrors were in quadrant configuration with photons being reflected consecutively in the primary and secondary stage before landing on the focal plane of 5.6 m away from the interface between the two stages. The reflectors of the mirror are made of heat-formed aluminum substrate of the thickness gauged of 152 m, 229 m, and 305 m of the alloy 5052 H-19, followed by epoxy replication on gold-sputtered smooth Pyrex cylindrical mandrels to acquire the X-ray reflective surface. The epoxy layer is 10 m nominal and surface gold layer of 0.2 m. Improvements on angular response over its predecessors, e.g. Astro-E1/Suzaku mirrors, come from error reduction on the figure, the roundness, and the grazing angle/radius mismatching of the reflecting surface, and tighter specs and mechanical strength on supporting structure to reduce the reflector positioning and the assembly errors. Each soft x-ray telescope (SXT), FM1 or FM2, were integrated from four independent quadrants of mirrors. The stray-light baffles, in quadrant configuration, were mounted onto the integrated mirror. Thermal control units were attached to the perimeter of the integrated mirror to keep the mirror within operating temperature in space. The completed instrument went through a series of optical alignment, thus made the quadrant images confocal and their optical axes in parallel to achieve highest throughput possible. Environmental tests were carried out, and optical quality of the telescopes has been confirmed. The optical and x-ray calibrations also include

  7. Sub-arcsec X-Ray Telescope for Imaging The Solar Corona In the 0.25 - 1.2 keV Band

    NASA Technical Reports Server (NTRS)

    Gallagher, Dennis; Cash, Webster; Jelsma, Schuyler; Farmer, Jason

    1996-01-01

    We have developed an X-ray telescope that uses a new technique for focusing X-rays with grazing incidence optics. The telescope was built with spherical optics for all of its components, utilizing the high quality surfaces obtainable when polishing spherical (as opposed to aspherical) optics. We tested the prototype X-ray telescope in the 300 meter vacuum pipe at White Sands Missile Range, NM. The telescope features 2 degee graze angles with tungsten coatings, yielding a bandpass of 0.25-1.5 keV with a peak effective area of 0.8 sq cm at 0.83 keV. Results from X-ray testing at energies of 0.25 keV and 0.93 keV (C-K and Cu-L) verify 0.5 arcsecond performance at 0.93 keV. Results from modeling the X-ray telescope's response to the Sun show that the current design would be capable of recording 10 half arcsecond images of a solar active region during a 300 second NASA sounding rocket flight.

  8. Microwave Kinetic Inductance Detectors: Large Format X-ray Spectral Imagers for the Next Generation of X-ray Telescopes

    NASA Astrophysics Data System (ADS)

    Eckart, Megan E.; Mazin, B. A.; Bumble, B.; Golwala, S. R.; Zmuidzinas, J.; Day, P. K.; Harrison, F. A.

    2006-09-01

    Microwave Kinetic Inductance Detectors (MKIDs) have the potential to provide megapixel imagers with few eV spectral resolution for future X-ray missions such as Gen-X. MKIDs offer the advantage over many other cryogenic detector technologies that they can be easily multiplexed, so that arrays with many thousand pixels are readily achievable. In addition, the readout electronics can be operated at room temperature, a significant advantage for space applications. MKIDs exploit the dependence of surface impedance of a superconductorwith the quasiparticle density. Quasiparticles are created by absorption of X-rays, with number proportional to the X-ray energy. The impedance change may be sensitively measured using a thin-film resonant circuit. The practical application of MKIDs for photon detection requires a method of efficiently coupling the photon energy to the MKID. To apply the MKID scheme to X-ray detection we pattern tantalum strips with aluminum MKIDs attached at each end. An incident X-ray is absorbed in the Ta and creates millions of quasiparticle excitations, which diffuse to each end of the strip, finally entering the Al resonators where they are trapped and sensed. Simultaneous monitoring of the signal at both ends of the strip allow position and energy determination for each photon. We have demonstrated working strip detectors in the laboratory, and will present our measurements of the quasiparticle diffusion constant and the quasiparticle lifetime in tantalum, the aluminum quasiparticle lifetime, and the energy resolution of the detector. We will also discuss ideas for future detector designs and suggest ultimate performance goals for X-ray astronomy applications.

  9. The Operation and Evolution of the Swift X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Kennea, Jamie; Burrows, D. N.; Pagani, C.; Hill, Joanne; Racusin, J. L.; Morris, D. C.; Abbey, A. F.; Beardmore, A. P.; Campana, G.; Chincarini, G.; Cusumano, G.; Evans, P. A.; Gehrels, N.; Godet, O.; Mineo, T.; LaParola, V.; Mangano, V.; Moretti, A.; Nousek, J. A.; Osborne, J. P.; Page, K. L.; Perri, M.; Starling, R. L. C.; Tagliaferri, G.; Tamburelli, F.

    2007-01-01

    The Swift X-ray Telescope (XRT) is a CCD based X-ray telescope designed for localization, spectroscopy and long term light curve monitoring of Gamma-Ray Bursts and their X-ray afterglows. Since the launch of Swift in November 2004, the XRT has undergone significant evolution in the way it is operated. Shortly after launch there was a failure of the thermo-electric cooler on the XRT CCD, which led to the XRT team being required to devise a method of keeping the XRT CCD temperature below 50C utilizing only passive cooling by minimizing the exposure of the XRT radiator to the Earth. We present in this paper an update on how the modeling of this passive cooling method has improved in first -1000 days since the method was devised, and the success rate of this method in day-to-day planning. We also discuss the changes to the operational modes and onboard software of the XRT. These changes include improved rapid data product generation in order to improve speed of rapid Gamma-Ray Burst response and localization to the community; changes to the way XRT observation modes are chosen in order to better fine tune data aquisition to a particular science goal; reduction of "mode switching" caused by the contamination of the CCD by Earth light or high temperature effects.

  10. Hard X-ray Polarimetry With Wide Band Laue Lens Telescopes

    NASA Astrophysics Data System (ADS)

    Caroli, E.

    2011-09-01

    Polarimetry is today considered a key observational parameter which can be used to help solve important scientific issues that are still open in the hard X-ray domain (above 10 keV). Therefore the ability to perform high sensitivity polarisation measurements has become a mandatory requirement for the next generation of space telescopes operating in this energy range. In particular the development of new high energy focusing optics, such as wide band Laue lenses operating from ~60 keV up to several hundred keV, with their 50-100 times better sensitivity with respect to current instrumentation, opens a real possibility to make hard X-ray polarimetry an almost standard measurement. Hard X-ray polarimetry can be performed using highly segmented focal plane detectors operated as scattering polarimeters. In this work we summarize results obtained by our group in a series of experiments with CZT/CdTe pixel detector prototypes operating as scattering polarimeters in the range between ~100-700 keV as well as Montecarlo evaluations of the achievable performance in polarisation measurements for Laue lens telescopes using focal planes based on CdTe/CZT pixel detectors.

  11. Application of an EMCCD Camera for Calibration of Hard X-Ray Telescopes

    SciTech Connect

    Vogel, J K; Pivovaroff, M J; Nagarkar, V V; Kudrolli, H; Madsen, K K; Koglin, J E; Christensen, F E; Brejnholt, N F

    2011-11-08

    Recent technological innovations now make it feasible to construct hard x-ray telescopes for space-based astronomical missions. Focusing optics are capable of improving the sensitivity in the energy range above 10 keV by orders of magnitude compared to previously used instruments. The last decade has seen focusing optics developed for balloon experiments and they will soon be implemented in approved space missions such as the Nuclear Spectroscopic Telescope Array (NuSTAR) and ASTRO-H. The full characterization of x-ray optics for astrophysical and solar imaging missions, including measurement of the point spread function (PSF) as well as scattering and reflectivity properties of substrate coatings, requires a very high spatial resolution, high sensitivity, photon counting and energy discriminating, large area detector. Novel back-thinned Electron Multiplying Charge-Coupled Devices (EMCCDs) are highly suitable detectors for ground-based calibrations. Their chip can be optically coupled to a microcolumnar CsI(Tl) scintillator via a fiberoptic taper. Not only does this device exhibit low noise and high spatial resolution inherent to CCDs, but the EMCCD is also able to handle high frame rates due to its controllable internal gain. Additionally, thick CsI(Tl) yields high detection efficiency for x-rays. This type of detector has already proven to be a unique device very suitable for calibrations in astrophysics: such a camera was used to support the characterization of the performance for all NuSTAR optics. Further optimization will enable similar cameras to be improved and used to calibrate x-ray telescopes for future space missions. In this paper, we discuss the advantages of using an EMCCD to calibrate hard x-ray optics. We will illustrate the promising features of this detector solution using examples of data obtained during the ground calibration of the NuSTAR telescopes performed at Columbia University during 2010/2011. Finally, we give an outlook on ongoing

  12. Development of an X-ray Telescope with a Large Effective Area for the Iron K Line Band

    NASA Astrophysics Data System (ADS)

    Matsumoto, Hironori; Tachibana, Sasagu; Yoshikawa, Shun; Tamura, Keisuke; Mori, Hideyuki; Mitsuishi, Ikuyuki; Tawara, Yuzuru; Kunieda, Hideyo; Yamashita, Kojun

    2015-08-01

    X-ray micro-calorimeters such as the Soft X-ray Spectrometer (SXS) on board ASTRO-H will enable precise spectroscopy of iron K lines even for spatially extended objects. To exploit the full power of the high-energy resolution, X-ray telescopes with a large effective area around 6 keV are essentially important. Conventional Wolter-I X-ray telescopes aimed at X-rays below 10 keV have used the principle of total reflection to collect the X-rays. Enlarging the diameter of this type of telescopes is not effective to obtain the large effective area, since the incident angle of X-rays for the outer part of the telescope exceeds the critical angle, and the X-ray reflectivity of the outer part is significantly low. For example, the critical angle of Ir for an X-ray of 6 keV is 0.748 deg. Thus if we assume a focal length of 6 m for a Wolter-I optics using mirrors covered with Ir as a reflector, the mirrors the radial position of which are larger than 34 cm cannot reflect X-rays above 6 keV effectively. If multi-layer mirrors are applied to the outer part of the telescope, however, the X-ray reflectivity can be enhanced significantly by the principle of Bragg reflection. Our objective is to develop a Wolter-I X-ray telescope with an aperture of 110 cm and a focal length of 6 m, and make all mirrors in the telescope can reflect X-rays around 6 keV effectively by utilizing the multi-layer mirrors. The size of the telescope is determined by a boundary condition that can be launched by the epsilon rocket of ISAS/JAXA. The multi-layer is designed to enhance the reflectivity at 6.4 keV, 6.7 keV, or 6.9 keV. Our simulation suggests that the effective area averaged in the 5.7-7.7 keV band could be 2000 cm2, whichis comparable to the effective area of Athena launched in 2028 by ESA. Furthermore, we showed that the Ir/C multi-layers produced by our DC magnetron sputtering machine has a surface roughness of less than 4 angstrom. This value is smaller than the average surface roughness

  13. Stellar X-ray activity in the Hyades

    NASA Technical Reports Server (NTRS)

    Stern, R. A.; Zolcinski, M.-C.

    1983-01-01

    Preliminary results from monitoring the X-ray emission of about 20 Hyades stars both on short and long time scales are reported. All observations were made with the Imaging Proportional Counter of the Einstein Observatory. The preliminary conclusions are that flaring behavior is probably common in the Hyades, but that the influence of binarity on the level of flaring activity needs to be investigated further. The long-term observations suggest that intrinsic differences in the level of stellar X-ray luminosity may be required to account for the spread in the X-ray luminosity function for solar-type stars observed in the original survey by Stern et al. (1981).

  14. Optical performance of grazing incidence X-ray/EUV telescopes for space science applications

    NASA Astrophysics Data System (ADS)

    Thompson, Patrick Louis

    In order to improve and expand the field of X-ray astronomy, and imaging in general, we find that these days a comprehensive systems engineering approach to X-ray image formation must be undertaken. While some industrial interests have taken steps in this direction, any academic approach is lacking from within the archival literature to date, and there are virtually no established university courses. Indeed, it would seem that top level, optical-systems-engineering is exclusively reserved for those seasoned professionals who have accumulated (though somewhat artistically) the ``know-how'' to efficiently conceive and implement excellent optical designs. Such expert knowledge is not and should not be mysterious. To this end, we attempt to formulate a highly comprehensive approach to X-ray optical systems engineering and implement it within the context of the Wolter Type-I and Type-II (grazing incidence) telescopes currently utilized for practical X-ray/EUV astronomy. In addition, we will transform the classical paraboloid- hyperboloid designs into `aplanatic' and `isoplanatic', hyperboloid-hyperboloid systems, where certain coma conditions are minimized. As will be shown, one gains little improvement in performance when choosing a quasi-aplanatic mirror design over a classical one, owing to scatter and other image degradation effects. Next we will show that a generalized hyperboloid-hyperboloid design can be comprehensively optimized for any imaging requirement, where the operational field-of-view is weighted according to spatial information content. Our H-H design has been optimized for the GOES Solar X-ray Imager mission and adopted by NASA and NOAA. It is currently undergoing fabrication by Raytheon Optical Systems Inc. who is under subcontract to the Lockheed-Martin Solar and Astrophysics Laboratory. Our design is expected to result in an 80% increase in optical system performance over the original SXI baseline design.

  15. Optical design for ATHENA X-ray telescope based on slumped mirror segments

    NASA Astrophysics Data System (ADS)

    Proserpio, Laura; Breunig, Elias; Friedrich, Peter; Winter, Anita

    2014-07-01

    The Hot and Energetic Universe will be the focus of future ESA missions: in late 2013 the theme was selected for the second large-class mission in the Cosmic Vision science program. Fundamental questions on how and why ordinary matter assemble into galaxies and clusters, and how black holes grow and influence their surroundings can be addressed with an advanced X-ray observatory. The currently proposed ATHENA mission presents all the potentiality to answer the outstanding questions. It is based on the heritage of XMM-Newton and on the previous studies for IXO mission. The scientific payload will require state of the art instrumentations. In particular, the baseline for the X-ray optical system, delivering a combination of large area, high angular resolution, and large field of view, is the Silicon Pore Optics technology (SPO) developed by ESA in conjunction with the Cosine Measurement Systems. The slumping technology is also under development for the manufacturing of future X-ray telescopes: for several years the Max Planck Institute for Extraterrestrial physics (MPE) has been involved in the analysis of the indirect slumping approach, which foresees the manufacturing of segmented X-ray shells by shaping thin glass foils at high temperatures over concave moulds so to avoid any contact of the optical surface with other materials during the process, preserving in this way the original X-ray quality of the glass surface. The paper presents an alternative optical design for ATHENA based on the use of thin glass mirror segments obtained through slumping.

  16. Simbol-X: A New Generation Soft/Hard X-ray Telescope

    NASA Astrophysics Data System (ADS)

    Slane, Patrick O.; Romaine, S.; Murray, S. S.; Brissenden, R.; Elvis, M.; Gorenstein, P.; Steel, S.; O'Dell, S.; Kolodziejczak, J.; Ramsey, B.; Angelini, L.; Citterio, O.; Pareschi, G.

    2008-03-01

    Simbol-X is arguably the most powerful broad-band focusing hard (0.5-80 keV) X-ray telescope operating in the 2013 timeframe. The combination of good angular resolution, broad energy response, and efficient observing provided by a good field of view and high orbit will provide a very large increase in sensitivity in a hitherto relatively unexplored spectral region. This will enable key scientific investigations including a census of supermassive black holes in the crucial energy range in which the cosmic X-ray background peaks, measurements of the geometry and dynamics of accretion in black hole binaries, characterization of hard X-ray sources in the Galactic center, and the nature and origin of energetic particles in galaxy clusters and supernova remnants. Its single optics module contains a set of nested nickel shells coated with multilayers to boost the high-energy response and the field of view. Its focal plane detectors are a novel hybrid configuration, with thick-depletion silicon providing the low energy response, and Cadmium Telluride the high energy response. To achieve the long focal length necessary for large collecting areas at high energies, the optics and detectors are on separate high-earth-orbit formation-flying spacecrafts, 20 m apart. We describe a proposed US participation in the Simbol-X program to provide technical expertise in the area of multilayer coatings for the X-ray optics; expertise in science and the X-ray testing and calibration of the flight optics; and support as a data analysis, Guest Investigator, and archiving center. The use of the NASA DSN Goldstone station, as a complement to the Malindi tracking station,will also be provided.

  17. Realization and drive tests of active thin glass x-ray mirrors

    NASA Astrophysics Data System (ADS)

    Spiga, D.; Barbera, M.; Collura, A.; Basso, S.; Candia, R.; Civitani, M.; Di Cicca, G.; Lo Cicero, U.; Lullo, G.; Pelliciari, C.; Salmaso, B.; Sciortino, L.; Varisco, S.

    2016-09-01

    A technique to obtain lightweight and high-resolution focusing mirror segments for large aperture X-ray telescopes is the hot slumping of thin glass foils. In this approach, already successfully experimented to manufacture the optics of the NuSTAR X-ray telescope, thin glasses are formed at high temperature onto a precisely figured mould. The formed glass foils are subsequently stacked onto a stiff backplane with a common axis and focus to form an XOU (X-ray Optical Unit), to be later integrated in the telescope optic structure. In this process, the low thickness of the glass foils guarantees a low specific mass and a very low obstruction of the effective area. However, thin glasses are subject to deformations that may arise at any stage of the production process, thereby degrading the angular resolution. To solve this problem, several groups are working on the possibility to correct the mirror profile post-manufacturing, using piezoelectric elements exerting a tangential strain on the non-optical side of the glass mirrors. In this paper we show the results of the approach we have adopted, based on the application of piezoceramic patches on the backside of thin glass foils, previously formed by hot slumping. The voltage signals are supplied to the piezoelectric elements by a system of electrodes deposited on the same side of the mirror via a photolithographic process. Finally, the matrix of voltages to be used to correct the mirror shape can be determined in X-rays illumination by detection of the intra-focal image and consequent reconstruction of the longitudinal profile. We describe the production of some active mirrors with different arrangements of piezoelectric elements and the X-ray tests performed at the XACT X-ray facility to determine the optimal actuator geometry.

  18. Active Galaxy Winds from X-ray, Ultraviolet, and Optical Studies of Nearby Seyfert 1s

    NASA Astrophysics Data System (ADS)

    Winter, Lisa M.

    2012-01-01

    Mass outflows or winds from active galaxies may profoundly affect the evolution of their host galaxies by blowing away gas from star forming regions and recycling metals from near-nuclear supernovae into the galaxy disk. Such fundamental properties as the covering fraction, total energy, variability, and distance of these outflows are still unknown. We present new results in an effort to better understand the properties of active galaxy winds based on X-ray, optical, and UV observations of local Seyfert 1s. We show that the covering fraction, indicated through X-ray and optical spectroscopy, is higher than previous studies suggest. We also show new observations in the UV with the Hubble Space Telescope's Cosmic Origins Spectrograph (COS), showing that the UV variability is at a much lower level than X-ray variability. The COS observations also reveal weak Ly-alpha outflows, which were difficult/impossible to detect in previous generations of UV spectrographs.

  19. Preflare characteristics of active regions observed in soft X-rays

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.

    1979-01-01

    X-ray images from the AS&E telescope on Skylab are used to investigate coronal conditions in solar active regions during the 20-min periods preceding the X-ray onsets of small flares. The preflare or precursor phase is defined as a phase with a characteristic length or time scale significantly different from that of the rise phase. We show that there is no observational evidence of a requirement for a coronal preflare heating phase with a time scale longer than 2 min for small flares characterized by one or two loops. In 18 out of 25 cases the flaring X-ray structure was not the brightest feature in the preflare active region. The electron densities are estimated for preflare loops.

  20. Aligning, Bonding, and Testing Mirrors for Lightweight X-ray Telescopes

    NASA Technical Reports Server (NTRS)

    Chan, Kai-Wing; Zhang, William W.; Saha, Timo T.; McClelland, Ryan S.; Biskach, Michael P.; Niemeyer, Jason; Schofield, Mark J.; Mazzarella, James R.; Kolos, Linette D.; Hong, Melinda M.; Numata, Ai; Sharpe, Marton V.; Solly, Peter M.; Riveros, Raul E.; Allgood, Kim D.; McKeon, Kevin P.

    2015-01-01

    High-resolution, high throughput optics for x-ray astronomy entails fabrication of well-formed mirror segments and their integration with arc-second precision. In this paper, we address issues of aligning and bonding thin glass mirrors with negligible additional distortion. Stability of the bonded mirrors and the curing of epoxy used in bonding them were tested extensively. We present results from tests of bonding mirrors onto experimental modules, and on the stability of the bonded mirrors tested in x-ray. These results demonstrate the fundamental validity of the methods used in integrating mirrors into telescope module, and reveal the areas for further investigation. The alignment and integration methods are applicable to the astronomical mission concept such as STAR-X, the Survey and Time-domain Astronomical Research Explorer.

  1. Technology Development for the Constellation-X Spectroscopy X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Petre, Robert; Lehan, John; O'Dell, Stephen; Owens, Scott; Reid, Paul B.; Saha, Timo; Stewart, Jeff; Jones, William D.; Zhang, William

    2005-01-01

    The Constellation-X Spectroscopy X-ray Telescope (SXT) is a large diameter, high throughput, grazing incidence imaging mirror system, designed to perform high sensitivity spectroscopy of cosmic X-ray sources in the 0.2-10.0 keV band. The baseline effective area requirement is -3 m# at 1 keV. The system-level angular-resolution requirement is a 15-arcseconds half-power diameter, with a 5-arcsecond goal. The effective area is attained through a modular design, involving the nesting of many confocal, thin-walled Wolter I mirror segments. Considerable progress has been made in developing thin, thermally formed, glass mirror substrates that meet or better the angular-resolution requirement. Several approaches to mounting and aligning reflector segments into a mirror system are under investigation. We report here on the progress of the SXT technology development program toward reaching the performance goals.

  2. Aligning, bonding, and testing mirrors for lightweight x-ray telescopes

    NASA Astrophysics Data System (ADS)

    Chan, Kai-Wing; Zhang, William W.; Saha, Timo T.; McClelland, Ryan S.; Biskach, Michael P.; Niemeyer, Jason; Schofield, Mark J.; Mazzarella, James R.; Kolos, Linette D.; Hong, Melinda M.; Numata, Ai; Sharpe, Marton V.; Solly, Peter M.; Riveros, Raul E.; Allgood, Kim D.; McKeon, Kevin P.

    2015-09-01

    High-resolution, high throughput optics for x-ray astronomy entails fabrication of well-formed mirror segments and their integration with arc-second precision. In this paper, we address issues of aligning and bonding thin glass mirrors with negligible additional distortion. Stability of the bonded mirrors and the curing of epoxy used in bonding them were tested extensively. We present results from tests of bonding mirrors onto experimental modules, and on the stability of the bonded mirrors tested in x-ray. These results demonstrate the fundamental validity of the methods used in integrating mirrors into telescope module, and reveal the areas for further investigation. The alignment and integration methods are applicable to the astronomical mission concept such as STAR-X, the Survey and Time-domain Astronomical Research Explorer.

  3. Hard X-Ray Telescope (HXT) with Simultaneous Multiwavelength Observing from UV to 1 MeV

    NASA Technical Reports Server (NTRS)

    Gorenstein, Paul

    1998-01-01

    The Hard X-Ray Telescope Mission Concept Study no longer exists as a possible independent mission. The grazing incidence multilayer telescopes, its major component, are now firmly attached to the Constellation X-Ray Mission. It was determined that the most efficient deployment of a hard X-ray (10 to 100 keV) focussing telescope system is observing simultaneously with a high throughput lower energy spectrometer, providing the rationale for merging with Constellation X. This configuration permits four nearly four decades in energy (.2 to 100 keV) of an object's emission spectrum to be studied simultaneously with good energy resolution. Furthermore, the probability of attaining an independent mission for a hard X-ray telescope system is extremely low.

  4. Hard x-ray telescopes to be onboard ASTRO-H.

    PubMed

    Awaki, Hisamitsu; Kunieda, Hideyo; Ishida, Manabu; Matsumoto, Hironori; Babazaki, Yasunori; Demoto, Tadatsugu; Furuzawa, Akihiro; Haba, Yoshito; Hayashi, Takayuki; Iizuka, Ryo; Ishibashi, Kazunori; Ishida, Naoki; Itoh, Masayuki; Iwase, Toshihiro; Kosaka, Tatsuro; Kurihara, Daichi; Kuroda, Yuuji; Maeda, Yoshitomo; Meshino, Yoshifumi; Mitsuishi, Ikuyuki; Miyata, Yuusuke; Miyazawa, Takuya; Mori, Hideyuki; Nagano, Housei; Namba, Yoshiharu; Ogasaka, Yasushi; Ogi, Keiji; Okajima, Takashi; Saji, Shigetaka; Shimasaki, Fumiya; Sato, Takuro; Sato, Toshiki; Sugita, Satoshi; Suzuki, Yoshio; Tachibana, Kenji; Tachibana, Sasagu; Takizawa, Shunya; Tamura, Keisuke; Tawara, Yuzuru; Torii, Tatsuharu; Uesugi, Kentato; Yamashita, Koujun; Yamauchi, Shigeo

    2014-11-10

    The new Japanese x-ray astronomy satellite, ASTRO-H, will carry two identical hard x-ray telescopes (HXTs), which cover the energy range of 5 to 80 keV. The HXT mirrors employ tightly nested, conically approximated thin-foil Wolter-I optics, and the mirror surfaces are coated with Pt/C depth-graded multilayers to enhance the hard x-ray effective area by means of Bragg reflection. The HXT comprises foils 120-450 mm in diameter and 200 mm in length, with a focal length of 12 m. To obtain a large effective area, 213 aluminum foils 0.2 mm in thickness are tightly nested confocally. The requirements for HXT are a total effective area of >300  cm2 at 30 keV and an angular resolution of <1.7' in half-power diameter (HPD). Fabrication of two HXTs has been completed, and the x-ray performance of each HXT was measured at a synchrotron radiation facility, SPring-8 BL20B2 in Japan. Angular resolutions (HPD) of 1.9' and 1.8' at 30 keV were obtained for the full telescopes of HXT-1 and HXT-2, respectively. The total effective area of the two HXTs at 30 keV is 349  cm2.

  5. The Multi-Spectral Solar Telescope Array. II - Soft X-ray/EUV reflectivity of the multilayer mirrors

    NASA Technical Reports Server (NTRS)

    Barbee, Troy W., Jr.; Weed, J. W.; Hoover, Richard B. C., Jr.; Allen, Max J.; Lindblom, Joakim F.; O'Neal, Ray H.; Kankelborg, Charles C.; Deforest, Craig E.; Paris, Elizabeth S.; Walker, Arthur B. C.

    1992-01-01

    We have developed seven compact soft X-ray/EUV (XUV) multilayer coated and two compact FUV interference film coated Cassegrain and Ritchey-Chretien telescopes for a rocket borne observatory, the Multi-Spectral Solar Telescope Array. We report here on extensive measurements of the efficiency and spectral bandpass of the XUV telescopes carried out at the Stanford Synchrotron Radiation Laboratory.

  6. X-rays From Quasars and Active Galaxies

    NASA Technical Reports Server (NTRS)

    Lightman, Alan P.

    1981-01-01

    Features of quasars and active galactic nuclei are discussed and include: the nature of the power source, the radiation processes, and the mechanism for the formation and collimation of long-lived jets of matter observed to emanate from the center of these of these objects. The phenomena that produce X-rays are highlighted.

  7. GREEN BANK TELESCOPE AND SWIFT X-RAY TELESCOPE OBSERVATIONS OF THE GALACTIC CENTER RADIO MAGNETAR SGR J1745–2900

    SciTech Connect

    Lynch, Ryan S.; Archibald, Robert F.; Kaspi, Victoria M.; Scholz, Paul

    2015-06-20

    We present results from eight months of Green Bank Telescope 8.7 GHz observations and nearly 18 months of Swift X-ray telescope observations of the radio magnetar SGR J1745–2900. We tracked the radio and X-ray flux density, polarization properties, profile evolution, rotation, and single-pulse behavior. We identified two main periods of activity. The first is characterized by approximately 5.5 months of relatively stable evolution in radio flux density, rotation, and profile shape, while in the second these properties varied substantially. Specifically, a third profile component emerged and the radio flux also became more variable. The single pulse properties also changed, most notably with a larger fraction of pulses with pulse widths ∼5–20 ms in the erratic state. Bright single pulses are well described by a log-normal energy distribution at low energies, but with an excess at high energies. The 2–10 keV flux decayed steadily since the initial X-ray outburst, while the radio flux remained stable to within ∼20% during the stable state. A joint pulsar timing analysis of the radio and X-ray data shows a level of timing noise unprecedented in a radio magnetar, though during the time covered by the radio data alone the timing noise was at a level similar to that observed in other radio magnetars. While SGR J1745–2900 is similar to other radio magnetars in many regards, it differs by having experienced a period of relative stability in the radio that now appears to have ended, while the X-ray properties evolved independently.

  8. First peek of ASTRO-H Soft X-ray Telescope (SXT) in-orbit performance

    NASA Astrophysics Data System (ADS)

    Okajima, Takashi; Soong, Yang; Serlemitsos, Peter; Mori, Hideyuki; Olsen, Larry; Robinson, David; Koenecke, Richard; Chang, Bill; Hahne, Devin; Iizuka, Ryo; Ishida, Manabu; Maeda, Yoshitomo; Sato, Toshiki; Kikuchi, Naomichi; Kurashima, Sho; Nakaniwa, Nozomi; Hayashi, Takayuki; Ishibashi, Kazunori; Miyazawa, Takuya; Tachibana, Kenji; Tamura, Keisuke; Furuzawa, Akihiro; Tawara, Yuzuru; Sugita, Satoshi

    2016-07-01

    ASTRO-H (Hitomi) is a Japanese X-ray astrophysics satellite just launched in February, 2016, from Tanegashima, Japan by a JAXA's H-IIA launch vehicle. It has two Soft X-ray Telescopes (SXTs), among other instruments, that were developed by NASA's Goddard Space Flight Center in collaboration with ISAS/JAXA and Nagoya University. One is for an X-ray micro-calorimeter instrument (Soft X-ray Spectrometer, SXS) and the other for an X-ray CCD camera (Soft X-ray Imager, SXI), both covering the X-ray energy band up to 15 keV. The two SXTs were fully characterized at the 30-m X-ray beamline at ISAS/JAXA. The combined SXT+SXS system effective area is about 250 and 300 cm2 at 1 and 6 keV, respectively, although observations were performed with the gate valve at the dewar entrance closed, which blocks most of low energy X-rays and some of high energy ones. The angular resolution for SXS is 1.2 arcmin (Half Power Diameter, HPD). The combined SXT+SXI system effective area is about 370 and 350 cm2 at 1 and 6 keV, respectively. The angular resolution for SXI is 1.3 arcmin (HPD). The both SXTs have a field of view of about 16 arcmin (FWHM of their vignetting functions). The SXT+SXS field of view is limited to 3 x 3 arcmin by the SXS array size. In-flight data available to the SXT team was limited at the time of this conference and a point-like source data is not available for the SXT+SXS. Although due to lack of attitude information we were unable to reconstruct a point spread function of SXT+SXI, according to RXJ1856.5-3754 data, the SXT seems to be working as expected in terms of imaging capability. As for the overall effective area response for both SXT+SXS and SXT+SXI, consistent spectral model fitting parameters with the previous measurements were obtained for Crab and G21.5-0.9 data. On the other hand, their 2-10 keV fluxes differ by about 20% at this point. Calibration work is still under progress. The SXT is the latest version of the aluminum foil X-ray mirror, which is

  9. Design of hard x-ray focusing telescope with a large field-of-view

    NASA Astrophysics Data System (ADS)

    Chen, Shenghao; Mu, Baozhong; Ma, Shuang; Wang, Zhanshan

    2014-11-01

    X-ray Timing and Polarization (XTP) satellite with focusing optics and advanced detectors will study Black Hole, Neutron Star, Quark Star and the physics under extreme gravity, density and magnetism. XTP is about to make the most sensitive temporal and polarization observations with good energy resolution in 1-30 keV. We present the design of XTP Telescope with a larger field of view in this paper. The initial structure design of nested conical Wolter-I telescope in X-rays is determined with the focal length f=4.5m, mirror length L=100mm, thickness t=0.3mm, inner and outer diameter Din-out=100-450mm. To optimize the structure parameters, a self-complied Matlab software is used to maximize the center geometrical collecting are. A constant deviation gap between every two mirrors is introduced, and we calculate geometrical area in on-axis and off-axis. Balancing the performance of the telescope, the final gap value is 0.06 mm. The geometrical collecting area of on-axis decreased by 5%, the average geometrical area of off-axis is increased about 1.7% and the field of view is improved from 22' to 24', meanwhile, number of mirrors and total weight of mirrors also are decreased by 5.8%, 5.3% respectively.

  10. Industrialization scenario for X-ray telescopes production based on glass slumping

    NASA Astrophysics Data System (ADS)

    Proserpio, Laura; Döhring, Thorsten; Breunig, Elias; Friedrich, Peter; Winter, Anita

    2014-07-01

    Large X-ray segmented telescopes will be a key element for future missions aiming to solve still hidden mysteries of the hot and energetic Universe, such as the role of black holes in shaping their surroundings or how and why ordinary matter assembles into galaxies and clusters as it does. The major challenge of these systems is to guarantee a large effective area in combination with large field of view and good angular resolution, while maintaining the mass of the entire system within the geometrical and mass budget posed by space launchers. The slumping technology presents all the technical potentiality to be implemented for the realization of such demanding systems: it is based on the use of thin glass foils, shaped at high temperature in an oven over a suitable mould. Thousands of slumped segments are then aligned and assembled together into the optical payload. An exercise on the mass production approach has been conducted at Max Planck Institute for Extraterrestrial Physics (MPE) to show that the slumping technology can be a valuable approach for the realization of future X-ray telescopes also from a point of view of industrialization. For the analysis, a possible design for the ATHENA mission telescope was taken as reference.

  11. Optical Metrology for the Segmented Optics on the Constellation-X Spectroscopy X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Content, David; Colella, David; Fleetwood, Charles; Hadjimichael, Theo; Lehan, John; McMann, Joseph; Reid, Paul; Saha, Timo; Wright, Geraldine; Zhang, William

    2004-01-01

    We present the metrology requirements and metrology implementation necessary to prove out the reflector technology for the Constellation X(C-X) spectroscopy X-ray telescope (SXT). This segmented, 1.6m diameter highly nested Wolter-1 telescope presents many metrology and alignment challenges. In particular, these mirrors have a stringent imaging error budget as compared to their intrinsic stiffness; This is required for Constellation-X to have sufficient effective area with the weight requirement. This has implications for the metrology that can be used. A variety of contract and noncontact optical profiling and interferometric methods are combined to test the formed glass substrates before replication and the replicated reflector segments.The reflectors are tested both stand-alone and in-situ in an alignment tower.Some of these methods have not been used on prior X-ray telescopes and some are feasible only because of the segmented approach used on the SXT. Methods discussed include high precision coordinate measurement machines using very low force or optical probe axial interferometric profiling azimuthal circularity profiling and use of advanced null optics such as conical computer generated hologram (CGHs).

  12. Hard x-ray telescope concentrator for astrophysical mission Spectrum-X-Gamma

    NASA Astrophysics Data System (ADS)

    Pavlinsky, M.; Arefiev, V.; Churazov, E.; Gilfanov, M.; Grigorovich, S.; Litvin, D.; Lapshov, I.; Levin, V.; Akimov, V.; Semena, N.; Tkachenko, A.; Vikhlinin, A.; Sunyaev, R.; Ramsey, B. D.; Gubarev, M. V.; Elsner, R. F.; O'Dell, S. L.; Weisskopf, M. C.

    2007-09-01

    The hard X-ray telescope-concentrator ART-XC on board the Spectrum-X-Gamma X-ray astrophysical observatory (launching in 2011) is one of the main instruments of the mission. The instrument will be used for an all-sky survey and then for pointed observations which are planned for the first four and the next three years of the Mission, respectively. ART-XC will be sensitive in the 4-30 keV energy range and will have an effective area of several hundred square centimeters at 10 keV. It will have a field of view of about ~28 arcmin, angular resolution better than 1 arcmin and will be an order of magnitude more sensitive than the current generation of collimated instruments and coded mask telescopes in the survey mode and a two or three orders of magnitude more sensitive in the pointing mode. With its high sensitivity in the hard X-ray band and good imaging capabilities, ART-XC will extend the operating energy range of the observatory (complementing the capabilities of the primary science instrument eROSITA), thus significantly enhancing the mission both in the all-sky survey over the energy band 4-10 keV and, especially, in pointed observations over the energy band 4-30 keV. During the 4-year survey, this ART-XC would detect more than ~10 4 sources over 4-10 keV. For a 10 5 second pointed observation, the telescope will provide better than 10 microCrab sensitivity in the 4-20 keV energy range.

  13. NuSTAR X-ray observations of small flares and non-flaring active regions

    NASA Astrophysics Data System (ADS)

    Hannah, I. G.; Grefenstette, B.; Smith, D. M.; Marsh, A.; Glesener, L.; Krucker, S.; Hudson, H. S.; White, S.; Madsen, K.; Caspi, A.; Vogel, J.; Shih, A.

    2015-12-01

    We present imaging spectroscopy of the Sun with the NuSTAR hard X-ray (HXR) telescope, an astrophysics mission that uses focusing optics to directly image X-rays between ~2-80 keV. Although not optimized for solar observations, NuSTAR's high sensitivity can probe previously inaccessible X-ray emission from the Sun - crucial for searching for high temperature and non-thermal emission from "non-flaring" active regions. We present analysis of the first NuSTAR solar observations, that began in late 2014 and continued through 2015. These include using its imaging spectroscopy capabilities to derive the thermal characteristics of several "non-flaring" active regions, providing limits to the high temperature emission. We also show NuSTAR observations of several small microflares that were also observed by Hinode/XRT (in multiple thicker filters sensitive to higher temperatures) and RHESSI. This combination of three separate X-ray telescopes provides a broad observational characterization of active region heating by these very small microflares.

  14. Thin Mirror Shaping Technology for High-Throughput X-ray Telescopes

    NASA Astrophysics Data System (ADS)

    Schattenburg, Mark

    This proposal is submitted to the NASA Research Opportunities in Space and Earth Sciences program (ROSES-2012) in response to NASA Research Announcement NNH12ZDA001N- APRA. It is targeted to the Astronomy and Astrophysics Research and Analysis (APRA) program element under the Supporting Technology category. Powerful x-ray telescope mirrors are critical components of a raft of small-to-large mission concepts under consideration by NASA. The science questions addressed by these missions have certainly never been more compelling and the need to fulfill NASA s core missions of exploring the universe and strengthening our nation s technology base has never been greater. Unfortunately, budgetary constraints are driving NASA to consider the cost/benefit and risk factors of new missions more carefully than ever. New technology for producing x-ray telescopes with increased resolution and collecting area, while holding down cost, are key to meeting these goals and sustaining a thriving high-energy astrophysics enterprise in the US. We propose to develop advanced technology which will lead to thin-shell x-ray telescope mirrors rivaling the Chandra x-ray telescope in spatial resolution but with 10-100X larger area all at significantly reduced weight, risk and cost. The proposed effort builds on previous research at MIT and complements NASA-supported research at other institutions. We are currently pursuing two thin-mirror technology development tracks which we propose to extend and accelerate with NASA support. The first research track utilizes rapidly-maturing thermal glass slumping technology which uses porous ceramic air-bearing mandrels to shape glass mirrors without touching, thus avoiding surface-induced mid-range spatial frequency ripples. A second research track seeks to remove any remaining mid- to long-range errors in mirrors by using scanning ion-beam implant to impart small, highly deterministic and very stable amounts of stress into thin glass, utilizing local

  15. The Hubble Space Telescope observations of X-ray nova Muscae 1991 and its spectral evolution

    NASA Technical Reports Server (NTRS)

    Cheng, F. H.; Horne, Keith; Panagia, N.; Shrader, C. R.; Gilmozzi, R.; Paresce, F.; Lund, N.

    1992-01-01

    Hubble Space Telescope Faint Object Spectrograph (FOS) Faint Object Camera (FOC) and observations of Nova Muscae 1991 obtained on May 14-15, 1991 are presented and discussed. A nearly featureless continuum with broad 2200 A absorption feature and no Balmer jump is found. The FOS spectrum is modeled, including previous multiepoch IUE, optical, and X-ray data using a simple blackbody accretion disk model. It is found that the mass transfer rate decays exponentially with a characteristic time of about 43 days. The cooling front predicted by the disk instability model should have been observable, but was not seen.

  16. Development of an Energetic X-Ray Imaging Telescope Experiment (EXITE) and Associated Balloon Gondola System

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is the Final Report for grant NAGW-624, which was our original grant to develop the Energetic X- ray Imaging Telescope Experiment (EXITE) and Associated Balloon Gondola. The EXITE grant was changed over to a new grant (from GSFC), NAG5-5103, beginning in FY97 and is currently very much continuing under that grant. The Final Report presented here then covers the EXITE development under the original grant, which in fact continued (with a 1 year no-cost extension) through December 31, 1997.

  17. The Constellation-X Spectroscopy X-ray Telescope: Recent Technology Development

    NASA Technical Reports Server (NTRS)

    Petre, Robert; Lehan, John L.; Owens, Scott; Saha, Timo; Stewart, Jeff; Zhang, William W.; O'Dell, Stephen L.; Jones, Wiliam D.; Reid, Paul B.

    2006-01-01

    We describe recent progress in the technology development program for the mirror system for the Constellation-X Spectroscopy X-ray Telescope (SXT). Development of this mirror represents a significant technology challenge, as it must provide a combination of large effective area (3 sq. m) and modest angular resolution (15 arc second half power diameter requirement; 5 arc second goal) with a limited mass allocation. The baseline design incorporates over 200 nested Wolter 1 mirrors. Each of these in turn is segmented in order to simplify handling of the mirrors and facilitate mass production. The X-ray reflecting surfaces are fabricated from thin, thermally formed glass sheets. Production improvements have yielded mirror segments that approach the performance requirement without the need for epoxy replication. A mounting and alignment approach incorporating piezoelectric actuators has been shown to manipulate mirror segments with the required precision without introducing significant distortion. Substantial improvements in metrology methodology have provided insights into the mirror segment forming and alignment processes. An X-ray demonstration of a mirror segment pair is planned for early 2006.

  18. Variable magnification variable dispersion glancing incidence imaging x-ray spectroscopic telescope

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B. (Inventor)

    1991-01-01

    A variable magnification variable dispersion glancing incidence x-ray spectroscopic telescope capable of multiple high spatial revolution imaging at precise spectral lines of solar and stellar x-ray and extreme ultraviolet radiation sources includes a pirmary optical system which focuses the incoming radiation to a primary focus. Two or more rotatable carries each providing a different magnification are positioned behind the primary focus at an inclination to the optical axis, each carrier carrying a series of ellipsoidal diffraction grating mirrors each having a concave surface on which the gratings are ruled and coated with a mutlilayer coating to reflect by diffraction a different desired wavelength. The diffraction grating mirrors of both carriers are segments of ellipsoids having a common first focus coincident with the primary focus. A contoured detector such as an x-ray sensitive photogrpahic film is positioned at the second respective focus of each diffraction grating so that each grating may reflect the image at the first focus to the detector at the second focus. The carriers are selectively rotated to position a selected mirror for receiving radiation from the primary optical system, and at least the first carrier may be withdrawn from the path of the radiation to permit a selected grating on the second carrier to receive radiation.

  19. Variable magnification variable dispersion glancing incidence imaging x ray spectroscopic telescope

    NASA Technical Reports Server (NTRS)

    Hoover, Richard (Inventor)

    1990-01-01

    A variable magnification variable dispersion glancing incidence x ray spectroscopic telescope capable of multiple high spatial revolution imaging at precise spectral lines of solar and stellar x ray and extreme ultraviolet radiation sources includes a primary optical system which focuses the incoming radiation to a primary focus. Two or more rotatable carriers each providing a different magnification are positioned behind the primary focus at an inclination to the optical axis, each carrier carrying a series of ellipsoidal diffraction grating mirrors each having a concave surface on which the gratings are ruled and coated with a multilayer coating to reflect by diffraction a different desired wavelength. The diffraction grating mirrors of both carriers are segments of ellipsoids having a common first focus coincident with the primary focus. A contoured detector such as an x ray sensitive photographic film is positioned at the second respective focus of each diffraction grating so that each grating may reflect the image at the first focus to the detector at the second focus. The carriers are selectively rotated to position a selected mirror for receiving radiation from the primary optical system, and at least the first carrier may be withdrawn from the path of the radiation to permit a selected grating on the second carrier to receive radiation.

  20. Multi-spectral solar telescope array IV; The soft x-ray and extreme ultraviolet filters

    SciTech Connect

    Lindblom, J.F.; O'Neal, R.H.; Walker, A.B.C. Jr. ); Powell, F.R. ); Barbee, T.W. Jr. ); Hoover, R.B. ); Powell, S.F. )

    1991-08-01

    The multilayer mirrors used in the normal-incidence optical systems of the Multi-Spectral Solar Telescope Array (MSSTA) are efficient reflectors for soft x-ray/extreme ultraviolet (EUV) radiation at wavelengths that satisfy the Bragg condition, thus allowing a narrow band of the soft x-ray/EUV spectrum to be isolated. However, these same mirrors are also excellent reflectors in the visible, ultraviolet, and far-ultraviolet (FUV) part of the spectrum, where normal incidence reflectivities can exceed 50%. Furthermore, the sun emits far more radiation in the ultraviolet and visible part of the spectrum than it does in the soft x-ray/EUV. For this reason, thin foil filters are employed to eliminate the unwanted longer wavelength solar emission. The MSSTA instrument uses various combinations of thin foil filters composed of aluminum carbon, tellurium, potassium bromide, beryllium, molybdenum, rhodium, and phthalocyanine to achieve the desired radiation rejection characteristics. In this paper, the authors discuss issues concerning the design, manufacture, and predicted performance of MSSTA filters.

  1. Wide-field hard x-ray survey telescope: ProtoEXIST1

    NASA Astrophysics Data System (ADS)

    Hong, J.; Grindlay, J. E.; Chammas, N.; Allen, B.; Copete, A.; Said, B.; Burke, M.; Howell, J.; Gauron, T.; Baker, R. G.; Barthelmy, S. D.; Sheikh, S.; Gehrels, N.; Cook, W. R.; Burnham, J. A.; Harrison, F. A.; Collins, J.; Labov, S.; Garson, A., III; Krawczynski, H.

    2007-09-01

    We report our progress on the development of pixellated imaging CZT detector arrays for our first-generation balloon-borne wide-field hard X-ray (20 - 600 keV) telescope, ProtoEXIST1. Our ProtoEXIST program is a pathfinder for the High Energy Telescope (HET) on the Energetic X-ray Imaging Survey telescope (EXIST), a proposed implementation of the Black Hole Finder Probe. ProtoEXIST1 consists of four independent coded-aperture telescopes with close-tiled (~0.4 mm gaps) CZT detectors that preserve their 2.5mm pixel pitch. Multiple shielding/field-of-view configurations are planned to identify optimal geometry for the HET in EXIST. The primary technical challenge in ProtoEXIST is the development of large area, close-tiled modules of imaging CZT detectors (1000 cm2 for ProtoEXIST1), with all readout and control systems for the ASIC readout vertically stacked. We describe the overall telescope configuration of ProtoEXIST1 and review the current development status of the CZT detectors, from individual detector crystal units (DCUs) to a full detector module (DM). We have built the first units of each component for the detector plane and have completed a few Rev2 DCUs (2x2 cm2), which are under a series of tests. Bare DCUs (pre-crystal bonding) show high, uniform ASIC yield (~70%) and ~30% reduction in electronics noise compared to the Rev1 equivalent. A Rev1 DCU already achieved ~1.2% FWHM at 662 keV, and preliminary analysis of the initial radiation tests on a Rev2 DCU shows ~ 4 keV FWHM at 60 keV (vs. 4.7 keV for Rev1). We therefore expect about <=1% FWHM at 662 keV with the Rev2 detectors.

  2. Unwrapping the X-ray spectra of active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Reynolds, C. S.

    2016-05-01

    Active galactic nuclei (AGN) are complex phenomena. At the heart of an AGN is a relativistic accretion disk around a spinning supermassive black hole (SMBH) with an X-ray emitting corona and, sometimes, a relativistic jet. On larger scales, the outer accretion disk and molecular torus act as the reservoirs of gas for the continuing AGN activity. And on all scales from the black hole outwards, powerful winds are seen that probably affect the evolution of the host galaxy as well as regulate the feeding of the AGN itself. In this review article, we discuss how X-ray spectroscopy can be used to study each of these components. We highlight how recent measurements of the high-energy cutoff in the X-ray continuum by NuSTAR are pushing us to conclude that X-ray coronae are radiatively-compact and have electron temperatures regulated by electron-positron pair production. We show that the predominance of rapidly-rotating objects in current surveys of SMBH spin is entirely unsurprising once one accounts for the observational selection bias resulting from the spin-dependence of the radiative efficiency. We review recent progress in our understanding of fast (v˜ (0.1-0.3)c, highly-ionized (mainly visible in Fe XXV and Fe XXVI lines), high-column density winds that may dominate quasar-mode galactic feedback. Finally, we end with a brief look forward to the promise of Astro-H and future X-ray spectropolarimeters.

  3. A NEW COSMOLOGICAL DISTANCE MEASURE USING ACTIVE GALACTIC NUCLEUS X-RAY VARIABILITY

    SciTech Connect

    Franca, Fabio La; Bianchi, Stefano; Branchini, Enzo; Matt, Giorgio; Ponti, Gabriele

    2014-05-20

    We report the discovery of a luminosity distance estimator using active galactic nuclei (AGNs). We combine the correlation between the X-ray variability amplitude and the black hole (BH) mass with the single-epoch spectra BH mass estimates which depend on the AGN luminosity and the line width emitted by the broad-line region. We demonstrate that significant correlations do exist that allow one to predict the AGN (optical or X-ray) luminosity as a function of the AGN X-ray variability and either the Hβ or the Paβ line widths. In the best case, when the Paβ is used, the relationship has an intrinsic dispersion of ∼0.6 dex. Although intrinsically more disperse than supernovae Ia, this relation constitutes an alternative distance indicator potentially able to probe, in an independent way, the expansion history of the universe. With respect to this, we show that the new mission concept Athena should be able to measure the X-ray variability of hundreds of AGNs and then constrain the distance modulus with uncertainties of 0.1 mag up to z ∼ 0.6. We also discuss how our estimator has the prospect of becoming a cosmological probe even more sensitive than the current supernovae Ia samples by using a new dedicated wide-field X-ray telescope able to measure the variability of thousands of AGNs.

  4. Swift Observations of the Recent X-ray Activity of Eta Carinae

    NASA Astrophysics Data System (ADS)

    Kalil Liburd, Jamar; Corcoran, Michael F.; Morris, David C.; Theodore Gull, Kenji Hamaguchi, Thomas Madura, Mairan Teodoro, Nick Durofchalk, Caleb Gimar.

    2015-01-01

    The extremely massive Luminous Blue Variable binary star, Eta Carinae, lies 7,500 light years away, deep within the Homunculus nebula where vigorous Wind-Wind collisions between the primary star and the companion star generate high-energy gases that produce X-rays. Complex X-ray variations occur near periastron, the point of least stellar separation between the two stars. Understanding the variability in Eta Carinae's high-energy spectrum during this period gives us a better understanding of the system's physical and stellar properties. We present the processing techniques and background estimation methods used to process and analyze weekly observations done with Swift's X-ray Telescope during Eta Carinae's most recent periastron passage in 2014. We present analysis of Eta Carinae's current column density and compare it to that of previous cycles. The exact nature of Eta Carinae's X-ray minimum activity, which occurs every 5.54 years, is still unclear. A detailed understanding of the mechanisms of the X-ray deep minimum stage and the associated differences in column density in each cycle will contribute to a clearer understanding of the wind-driven mass-loss from this unique system.

  5. Observations of limb flares with a soft X-ray telescope. [flown on Skylab

    NASA Technical Reports Server (NTRS)

    Gibson, E. G.

    1976-01-01

    The structure and evolution of 26 limb flares have been observed with a soft X-ray telescope flown on Skylab. The results are: (1) One or more well defined loops were the only structures of flare intensity observed during the rise phase and near flare maximum, except for knots which were close to the resolution of the telescope; (2) the flare core features were always sharply defined during rise phase; and (3) for the twenty events which contained loops, the geometry of the structure near maximum was that of a loop in ten cases, a loop with a spike at the top in four cases, a cusp or triangle in four cases, and a cusp combined with a spike in another two cases. Based on observation of the original film, it is suggested that flares which underwent large scale deformations had become unstable to MHD kinks. This implies that these flares occurred in magnetic flux tubes through which significant currents were flowing.

  6. High throughput measurements of soft x-ray impurity emission using a multilayer mirror telescope

    SciTech Connect

    Stutman, D.; Tritz, K.; Delgado-Aparicio, L.; Finkenthal, M.; Suliman, G.; Roquemore, L.; Kaita, R.; Kugel, H.; Johnson, D.; Tamura, N.; Sato, K.; Sudo, S.; Tarrio, C.

    2006-10-15

    A 4 in. multilayer mirror telescope has been tested on National Spherical Torus Experiment (NSTX) for high throughput measurements of the beam excited soft x-ray impurity emission. The design is aimed at imaging low-k turbulent fluctuations in the plasma core. The test device used curved and planar Mo/Si mirrors to focus with {approx_equal}15% optical transmission and few angstrom bandwidths, the 135 A ring Ly{sub {alpha}} line from injected Li III atoms, or the n=2-4 line from intrinsic C VI ions. As test detectors we used 1 cm{sup 2} absolute extreme ultraviolet diodes, equipped with 400 kHz bandwidth, low noise preamplifiers. With the available view on NSTX the telescope successfully detected small impurity density fluctuations associated with 1/1 modes rotating at midradius, indicating that a high signal to noise ratio and cost effective core turbulence diagnostic is feasible based on this concept.

  7. SuperHERO: the next generation hard x-ray HEROES telescope

    NASA Astrophysics Data System (ADS)

    Gaskin, Jessica A.; Christe, Steven D.; Elsner, Ronald F.; Kilaru, Kiranmayee; Ramsey, Brian D.; Seller, Paul; Shih, Albert Y.; Stuchlik, David W.; Swartz, Douglas A.; Tennant, Allyn F.; Weddendorf, Bruce; Wilson, Matthew D.; Wilson-Hodge, Colleen A.

    2014-07-01

    SuperHERO is a new high-resolution, Long Duration Balloon-capable, hard-x-ray (20-75 keV) focusing telescope for making novel astrophysics and heliophysics observations. The SuperHERO payload, currently in its proposal phase, is being developed jointly by the Astrophysics Office at NASA Marshall Space Flight Center and the Solar Physics Laboratory and the Wallops Flight Facility at NASA Goddard Space Flight Center. SuperHERO is a follow-on payload to the High Energy Replicated Optics to Explore the Sun (HEROES) balloon-borne telescope that recently flew from Fort Sumner, NM in September of 2013, and will utilize many of the same features. Significant enhancements to the HEROES payload will be made, including the addition of optics, novel solid-state multi-pixel CdTe detectors, integration of the Wallops Arc-Second Pointer and a significantly lighter gondola suitable for Long Duration Flights.

  8. Development of mirrors made of chemically tempered glass foils for future X-ray telescopes

    NASA Astrophysics Data System (ADS)

    Salmaso, Bianca; Civitani, Marta; Brizzolari, Claudia; Basso, Stefano; Ghigo, Mauro; Pareschi, Giovanni; Spiga, Daniele; Proserpio, Laura; Suppiger, Yves

    2015-10-01

    Thin slumped glass foils are considered good candidates for the realization of future X-ray telescopes with large effective area and high spatial resolution. However, the hot slumping process affects the glass strength, and this can be an issue during the launch of the satellite because of the high kinematical and static loads occurring during that phase. In the present work we have investigated the possible use of Gorilla® glass (produced by Corning®), a chemical tempered glass that, thanks to its strength characteristics, would be ideal. The un-tempered glass foils were curved by means of an innovative hot slumping technique and subsequently chemically tempered. In this paper we show that the chemical tempering process applied to Gorilla® glass foils does not affect the surface micro-roughness of the mirrors. On the other end, the stress introduced by the tempering process causes a reduction in the amplitude of the longitudinal profile errors with a lateral size close to the mirror length. The effect of the overall shape changes in the final resolution performance of the glass mirrors was studied by simulating the glass foils integration with our innovative approach based on glass reinforcing ribs. The preliminary tests performed so far suggest that this approach has the potential to be applied to the X-ray telescopes of the next generation.

  9. The Swift Burst Alert Telescope Detected Seyfert 1 Galaxies: X-Ray Broadband Properties and Warm Absorbers

    NASA Technical Reports Server (NTRS)

    Winter, Lisa M.; Veilleux, Sylvain; McKernan, Barry; Kallman, T.

    2012-01-01

    We present results from an analysis of the broadband, 0.3-195 keV, X-ray spectra of 48 Seyfert 1-1.5 sources detected in the very hard X-rays with the Swift Burst Alert Telescope (BAT). This sample is selected in an all-sky survey conducted in the 14-195 keV band. Therefore, our sources are largely unbiased toward both obscuration and host galaxy properties. Our detailed and uniform model fits to Suzaku/BAT and XMM-Newton/BAT spectra include the neutral absorption, direct power-law, reflected emission, soft excess, warm absorption, and narrow Fe I K[alpha] emission properties for the entire sample. We significantly detect O VII and O VIII edges in 52% of our sample. The strength of these detections is strongly correlated with the neutral column density measured in the spectrum. Among the strongest detections, X-ray grating and UV observations, where available, indicate outflowing material. The ionized column densities of sources with O VII and O VIII detections are clustered in a narrow range with Nwarm [approx] 1021 cm-2, while sources without strong detections have column densities of ionized gas an order of magnitude lower. Therefore, we note that sources without strong detections likely have warm ionized outflows present but at low column densities that are not easily probed with current X-ray observations. Sources with strong complex absorption have a strong soft excess, which may or may not be due to difficulties in modeling the complex spectra of these sources. Still, the detection of a flat [Gamma] [approx] 1 and a strong soft excess may allow us to infer the presence of strong absorption in low signal-to-noise active galactic nucleus spectra. Additionally, we include a useful correction from the Swift BAT luminosity to bolometric luminosity, based on a comparison of our spectral fitting results with published spectral energy distribution fits from 33 of our sources.

  10. Method of and means for testing a glancing-incidence mirror system of an X-ray telescope

    NASA Technical Reports Server (NTRS)

    Dailey, C. C. (Inventor)

    1977-01-01

    An apparatus was designed for measuring the resolution and efficiency of a glancing-incidence mirror system having an even number of coaxial and confocal reflecting surfaces for use in an X-ray telescope. A collimated beam of X-rays is generated by an X-ray laser and directed along the axis of the system so that the beam is incident on the reflecting surfaces and illuminates a predetermined area. An X-ray detector, such as a photographic film, is located at the common focus of the surfaces so that the image produced by the X-rays may be compared with a test pattern interposed between the laser and the system.

  11. Constraints on axino warm dark matter from X-ray observation at the Chandra telescope and SPI

    SciTech Connect

    Dey, Paramita; Mukhopadhyaya, Biswarup; Roy, Sourov; Vempati, Sudhir K. E-mail: biswarup@hri.res.in E-mail: vempati@cts.iisc.ernet.in

    2012-05-01

    A sufficiently long lived warm dark matter could be a source of X-rays observed by satellite based X-ray telescopes. We consider axinos and gravitinos with masses between 1 keV and 100 keV in supersymmetric models with small R-parity violation. We show that axino dark matter receives significant constraints from X-ray observations of Chandra and SPI, especially for the lower end of the allowed range of the axino decay constant f{sub a}, while the gravitino dark matter remains unconstrained.

  12. A Spectral Analysis of the Masuda Flare Using Yohkoh Hard X-Ray Telescope Pixon Reconstruction

    NASA Astrophysics Data System (ADS)

    Alexander, David; Metcalf, Thomas R.

    1997-11-01

    Masuda's discovery of a compact hard X-ray impulsive source at the apex of a flaring coronal loop has received a great deal of recent attention in the solar physics community. The Masuda flare, which occurred on 1992 January 13, exhibited evidence of energy deposition in a compact region some distance above the soft X-ray loop, suggesting, to some authors, a flare process similar to the classical model for two-ribbon flares proposed by Shibata et al. These conclusions were made on the basis of a maximum entropy method (MEM) reconstruction of the Yohkoh Hard X-Ray Telescope (HXT) observations. Recently, a new approach has been developed for reconstructing the spatial information from the HXT: that of pixon reconstruction, proposed by Metcalf et al. In this paper, we apply the pixon reconstruction technique to the event of 1992 January 13 and determine the temporal and spectral characteristics of the loop-top source. While our emphasis here is on the spectral properties of the Masuda flare, we also provide a brief comparison between the pixon reconstruction and that of MEM for the hard X-ray loop top. In carrying out the comparison between the methods, we have applied recent improvements to the instrument response functions and reconstruction algorithms. We have also identified a previously unknown effect of weak source suppression that was inherent in previous analyses and that significantly compromised the ability to study weak sources of hard X-ray emission in the presence of strong sources. The improved response functions and the better flux estimation used in this paper reduce (but do not eliminate) the effects of this suppression, and consequently, it should be noted that the MEM analysis presented in this paper is quite distinct from any that have been carried out previously. Our conclusions are that (a) a compact loop-top hard X-ray source exists with an impulsive temporal profile spanning the peak of the flare; (b) the loop-top source is nonthermal in nature

  13. Moduli Dark Matter and the Search for Its Decay Line using Suzaku X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Kusenko, Alexander; Loewenstein, Michael; Yanagida, Tsutomu T.

    2013-01-01

    Light scalar fields called moduli arise from a variety of different models involving supersymmetry and/or string theory; thus their existence is a generic prediction of leading theories for physics beyond the standard model. They also present a formidable, long-standing problem for cosmology. We argue that an anthropic solution to the moduli problem exists in the case of small moduli masses and that it automatically leads to dark matter in the form of moduli. The recent discovery of the 125 GeV Higgs boson implies a lower bound on the moduli mass of about a keV. This form of dark matter is consistent with the observed properties of structure formation, and it is amenable to detection with the help of x-ray telescopes. We present the results of a search for such dark matter particles using spectra extracted from the first deep x-ray observations of the Draco and Ursa Minor dwarf spheroidal galaxies, which are darkmatter- dominated systems with extreme mass-to-light ratios and low intrinsic backgrounds. No emission line is positively detected, and we set new constraints on the relevant new physics.

  14. Calibration of the NuSTAR High-energy Focusing X-ray Telescope.

    NASA Astrophysics Data System (ADS)

    Madsen, Kristin K.; Harrison, Fiona A.; Markwardt, Craig B.; An, Hongjun; Grefenstette, Brian W.; Bachetti, Matteo; Miyasaka, Hiromasa; Kitaguchi, Takao; Bhalerao, Varun; Boggs, Steve; Christensen, Finn E.; Craig, William W.; Forster, Karl; Fuerst, Felix; Hailey, Charles J.; Perri, Matteo; Puccetti, Simonetta; Rana, Vikram; Stern, Daniel; Walton, Dominic J.; Jørgen Westergaard, Niels; Zhang, William W.

    2015-09-01

    We present the calibration of the Nuclear Spectroscopic Telescope Array (NuSTAR) X-ray satellite. We used the Crab as the primary effective area calibrator and constructed a piece-wise linear spline function to modify the vignetting response. The achieved residuals for all off-axis angles and energies, compared to the assumed spectrum, are typically better than ±2% up to 40 keV and 5%-10% above due to limited counting statistics. An empirical adjustment to the theoretical two-dimensional point-spread function (PSF) was found using several strong point sources, and no increase of the PSF half-power diameter has been observed since the beginning of the mission. We report on the detector gain calibration, good to 60 eV for all grades, and discuss the timing capabilities of the observatory, which has an absolute timing of ±3 ms. Finally, we present cross-calibration results from two campaigns between all the major concurrent X-ray observatories (Chandra, Swift, Suzaku, and XMM-Newton), conducted in 2012 and 2013 on the sources 3C 273 and PKS 2155-304, and show that the differences in measured flux is within ˜10% for all instruments with respect to NuSTAR.

  15. CALIBRATION OF THE NuSTAR HIGH-ENERGY FOCUSING X-RAY TELESCOPE

    SciTech Connect

    Madsen, Kristin K.; Harrison, Fiona A.; Grefenstette, Brian W.; Miyasaka, Hiromasa; Forster, Karl; Fuerst, Felix; Rana, Vikram; Walton, Dominic J.; Markwardt, Craig B.; An, Hongjun; Bachetti, Matteo; Kitaguchi, Takao; Bhalerao, Varun; Boggs, Steve; Craig, William W.; Christensen, Finn E.; Hailey, Charles J.; Perri, Matteo; Puccetti, Simonetta; Stern, Daniel; and others

    2015-09-15

    We present the calibration of the Nuclear Spectroscopic Telescope Array (NuSTAR) X-ray satellite. We used the Crab as the primary effective area calibrator and constructed a piece-wise linear spline function to modify the vignetting response. The achieved residuals for all off-axis angles and energies, compared to the assumed spectrum, are typically better than ±2% up to 40 keV and 5%–10% above due to limited counting statistics. An empirical adjustment to the theoretical two-dimensional point-spread function (PSF) was found using several strong point sources, and no increase of the PSF half-power diameter has been observed since the beginning of the mission. We report on the detector gain calibration, good to 60 eV for all grades, and discuss the timing capabilities of the observatory, which has an absolute timing of ±3 ms. Finally, we present cross-calibration results from two campaigns between all the major concurrent X-ray observatories (Chandra, Swift, Suzaku, and XMM-Newton), conducted in 2012 and 2013 on the sources 3C 273 and PKS 2155-304, and show that the differences in measured flux is within ∼10% for all instruments with respect to NuSTAR.

  16. Light weight optics made by glass thermal forming for future x-ray telescopes

    NASA Astrophysics Data System (ADS)

    Winter, Anita; Vongehr, Monika; Friedrich, Peter

    2010-07-01

    Future X-ray observatory missions, such as IXO or Gen-X, require grazing incidence optics of large collecting area in combination with a very good angular resolution. Wolter type I X-ray telescopes made of slumped glass segments could be a possible alternative to silicon pore optics. To achieve these requirements we develop slumping methods for high accuracy segments by experimental means. In particular, we follow the approach of indirect slumping and aim to produce parabola and hyperbola in one piece. In order to avoid internal stress in the glass segments the thermal expansion coefficient of the glass should closely match the thermal expansion of the mould material. Currently we focus on a combination of the alloy KOVAR for the mould and D263 for the glass; additionally a platinum-coated silica as mould material is studied. We investigate the behaviour of both materials during slumping in order to obtain the ideal environment for the slumping process. Additionally we report on the design of different metrology methods to measure the figure and thickness variations of the glass segments in visual light, e.g. interference, and on bearings used for shape measurements and integration.

  17. Continuing data analysis of the AS/E grazing incidence X-ray telescope experiment on the OSO-4 satellite

    NASA Technical Reports Server (NTRS)

    Vaiana, G.; Haggerty, R.; Kahler, S.; Krieger, A.; Landini, M.; Timothy, A.; Webb, D.

    1973-01-01

    The work to correct and extend the calculation of the theoretical solar X-ray spectrum produced during earlier OSO-4 data analysis is reported along with the work to formulate models of active regions, and compare these models with the experimental values. An atlas of solar X-ray photographs is included, and solar X-ray observations are correlated with the solar wind.

  18. SuperHERO: The Next Generation Hard X-Ray Focusing Telescope

    NASA Astrophysics Data System (ADS)

    Gaskin, Jessica; Wilson-Hodge, Colleen; Ramsey, Brian; Elsner, Ronald; Tennant, Allyn F.; Kilaru, Kiranmayee; Swartz, Douglas A.; Christe, Steven; Shih, Albert Y.; Baganoff, Frederick K.; Seller, Paul; Wilson, Matthew; Stuchlik, David

    2015-01-01

    SuperHERO is a balloon-borne hard x-ray (20-75 keV) telescope that couples high-angular resolution (~20 arcsecs) electroformed-nickel grazing incidence optics to state-of-the-art fine pixel-pitch (250 µm) Cadmium-Telluride detectors with a 6 m focal length. This telescope, currently in the proposal phase, will have the highest angular resolution of any hard x-ray telescope to date, and comparable energy resolution to that of the Nuclear Spectroscopic Telescope Array. The high angular resolution afforded by focusing optics is essential for mitigating source confusion in crowded fields, for direct imaging of extended sources on fine spatial scales, and for efficient observing through greatly-increased sensitivity. As such, the primary astronomical targets are the Galactic Center, pulsar-powered synchrotron nebulae and diffusive shock accelerated sites in supernova remnants. To facilitate solar observations, the SuperHERO detectors have a high processing rate of ~10 kHz over the entire 80x80 pixel array, or over 5M photons per second over the detector area. The current SuperHERO configuration has a total on-axis effective area of 145 cm2 at 30 keV and a field of view of ~7 arcmin FWHM at 30 keV (simulated). The optics, developed at NASA Marshall Space Flight Center, have significant flight heritage as similar mirrors have flown on balloon payloads, sounding rockets and a satellite mission. The detectors, developed at Rutherford Appleton Laboratory (RAL), utilize the novel HEXITEC Application Specific Integrated Circuit. RAL has been working on these and similar detectors for over a decade for applications ranging from medical to defense. NASA Goddard Space Flight Center, working with RAL and MSFC has been adapting these detectors for flight, with good progress. The telescope will reside on a carbon-composite frame that will integrate the Wallops Arc Second Pointer. This design will allow for Long Duration Balloon flights from Antarctica that can last up to 4 weeks

  19. Simulation of the Simbol-X telescope: imaging performance of a deformable x-ray telescope

    NASA Astrophysics Data System (ADS)

    Chauvin, Maxime; Roques, Jean-Pierre

    2009-08-01

    We have developed a simulation tool for a Wolter I telescope subject to deformations. The aim is to understand and predict the behavior of Simbol-X and other future missions (NuSTAR, Astro-H, IXO, ...). Our code, based on Monte-Carlo ray-tracing, computes the full photon trajectories up to the detector plane, along with the deformations. The degradation of the imaging system is corrected using metrology. This tool allows to perform many analyzes in order to optimize the configuration of any of these telescopes.

  20. On-Orbit Performance and Calibration of the Soft X-Ray Telescope on Yohkoh

    NASA Astrophysics Data System (ADS)

    Acton, Loren W.

    2016-02-01

    This paper documents details of the on-orbit performance, data problem solving, and calibration of the Soft X-ray Telescope (SXT) experiment on Yohkoh. This information is important to a full understanding of the strengths and weaknesses of the SXT data set. The paper begins with summaries of SXT calibration issues and how they have been addressed, operational anomalies experienced during the mission, and a brief discussion of the SXT optical train. The following section on the accuracy of Yohkoh pointing determination provides information important for alignment of SXT images with each other and with other solar data. The remainder of the paper gives details of work by the experiment team to understand and ameliorate the many instrument anomalies and changes which impacted the scientific data.

  1. SWIFT X-RAY TELESCOPE MONITORING OF FERMI-LAT GAMMA-RAY SOURCES OF INTEREST

    SciTech Connect

    Stroh, Michael C.; Falcone, Abe D.

    2013-08-15

    We describe a long-term Swift monitoring program of Fermi gamma-ray sources, particularly the 23 gamma-ray ''sources of interest''.We present a systematic analysis of the Swift X-Ray Telescope light curves and hardness ratios of these sources, and we calculate excess variability. We present data for the time interval of 2004 December 22 through 2012 August 31. We describe the analysis methods used to produce these data products, and we discuss the availability of these data in an online repository, which continues to grow from more data on these sources and from a growing list of additional sources. This database should be of use to the broad astronomical community for long-term studies of the variability of these objects and for inclusion in multiwavelength studies.

  2. From x-ray telescopes to neutron scattering: Using axisymmetric mirrors to focus a neutron beam

    NASA Astrophysics Data System (ADS)

    Khaykovich, B.; Gubarev, M. V.; Bagdasarova, Y.; Ramsey, B. D.; Moncton, D. E.

    2011-03-01

    We demonstrate neutron beam focusing by axisymmetric mirror systems based on a pair of mirrors consisting of a confocal ellipsoid and hyperboloid. Such a system, known as a Wolter mirror configuration, is commonly used in X-ray telescopes. The axisymmetric Wolter geometry allows nesting of several mirror pairs to increase collection efficiency. We implemented a system containing four nested Ni mirror pairs, which was tested by the focusing of a polychromatic neutron beam at the MIT Reactor. In addition, we have carried out extensive ray-tracing simulations of the mirrors and their performance in different situations. The major advantages of the Wolter mirrors are nesting for large angular collection and aberration-free performance. We discuss how these advantages can be utilized to benefit various neutron scattering methods, such as imaging, SANS, and time-of-flight spectroscopy.

  3. Ion implantation for figure correction of thin X-ray telescope mirror substrates

    NASA Astrophysics Data System (ADS)

    Chalifoux, Brandon; Wright, Graham; Heilmann, Ralf K.; Schattenburg, Mark L.

    2015-09-01

    Figure correction of X-ray telescope mirrors will be critical for future missions that require high angular resolution and large collecting areas. In this paper, we show that ion implantation offers a method of correcting figure errors by imparting sub-surface in-plane stress in a controllable magnitude and location in Schott D-263 glass, Corning Eagle XG glass, and crystalline silicon substrates. In addition, we can in theory achieve nearly exact corrections in Schott D-263 glass, by controlling the direction of the stress. We show that sufficient stress may be applied to Schott D-263 glass to achieve figure correction in mirrors with simulated initial figure errors. We also report on progress of a system that will be capable of correcting conical shell mirror substrates.

  4. Advanced flow-polishing and surface metrology of the SO56 X Ray Telescope

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The surface finishing of X ray grazing incidence optics is a most demanding area of optical processing, both in terms of metrology and application of optical finishing techniques. An existing optical mirror was processed using a new removal technique that uses a jet of finely dispersed and extremely small particles that impact a surface, which under the correct conditions, produces an ultrasmooth surface, especially on aspheric curvatures. The surfaces of the SO56 mirror are tapered conical shapes that have a continuously changing radius with the primary mirror having a parabolic shape and the secondary mirror a hyperbolic shape. An optical ray trace that was conducted of a telescope used the measured parameters from the existing substrates to set up the prescription for the optical layout. The optimization indicated a wavefront performance of 0.10 A at 0.633 micron.

  5. Chemical Bond Activation Observed with an X-ray Laser.

    PubMed

    Beye, Martin; Öberg, Henrik; Xin, Hongliang; Dakovski, Georgi L; Dell'Angela, Martina; Föhlisch, Alexander; Gladh, Jörgen; Hantschmann, Markus; Hieke, Florian; Kaya, Sarp; Kühn, Danilo; LaRue, Jerry; Mercurio, Giuseppe; Minitti, Michael P; Mitra, Ankush; Moeller, Stefan P; Ng, May Ling; Nilsson, Anders; Nordlund, Dennis; Nørskov, Jens; Öström, Henrik; Ogasawara, Hirohito; Persson, Mats; Schlotter, William F; Sellberg, Jonas A; Wolf, Martin; Abild-Pedersen, Frank; Pettersson, Lars G M; Wurth, Wilfried

    2016-09-15

    The concept of bonding and antibonding orbitals is fundamental in chemistry. The population of those orbitals and the energetic difference between the two reflect the strength of the bonding interaction. Weakening the bond is expected to reduce this energetic splitting, but the transient character of bond-activation has so far prohibited direct experimental access. Here we apply time-resolved soft X-ray spectroscopy at a free-electron laser to directly observe the decreased bonding-antibonding splitting following bond-activation using an ultrashort optical laser pulse.

  6. A SEARCH FOR FAST X-RAY VARIABILITY FROM ACTIVE GALACTIC NUCLEI USING SWIFT

    SciTech Connect

    Pryal, Matthew; Falcone, Abe; Stroh, Michael

    2015-03-20

    Blazars are a class of active galactic nuclei (AGNs) known for their very rapid variabilty in the high energy regions of the electromagnetic spectrum. Despite this known fast variability, X-ray observations have generally not revealed variability in blazars with rate doubling or halving timescales less than approximately 15 minutes. Since its launch, the Swift X-ray Telescope has obtained 0.2–10 keV X-ray data on 143 AGNs, including blazars, through intense target of opportunity observations that can be analyzed in a multiwavelength context and used to model jet parameters, particularly during flare states. We have analyzed this broad Swift data set in a search for short timescale variability in blazars that could limit the size of the emission region in the blazar jet. While we do find several low-significance possible flares with potential indications of rapid variability, we find no strong evidence for rapid (<15 minutes) doubling or halving times in flares in the soft X-ray energy band for the AGNs analyzed.

  7. X-Ray Psoralen Activated Cancer Therapy (X-PACT).

    PubMed

    Oldham, Mark; Yoon, Paul; Fathi, Zak; Beyer, Wayne F; Adamson, Justus; Liu, Leihua; Alcorta, David; Xia, Wenle; Osada, Takuya; Liu, Congxiao; Yang, Xiao Y; Dodd, Rebecca D; Herndon, James E; Meng, Boyu; Kirsch, David G; Lyerly, H Kim; Dewhirst, Mark W; Fecci, Peter; Walder, Harold; Spector, Neil L

    2016-01-01

    This work investigates X-PACT (X-ray Psoralen Activated Cancer Therapy): a new approach for the treatment of solid cancer. X-PACT utilizes psoralen, a potent anti-cancer therapeutic with current application to proliferative disease and extracorporeal photopheresis (ECP) of cutaneous T Cell Lymphoma. An immunogenic role for light-activated psoralen has been reported, contributing to long-term clinical responses. Psoralen therapies have to-date been limited to superficial or extracorporeal scenarios due to the requirement for psoralen activation by UVA light, which has limited penetration in tissue. X-PACT solves this challenge by activating psoralen with UV light emitted from novel non-tethered phosphors (co-incubated with psoralen) that absorb x-rays and re-radiate (phosphoresce) at UV wavelengths. The efficacy of X-PACT was evaluated in both in-vitro and in-vivo settings. In-vitro studies utilized breast (4T1), glioma (CT2A) and sarcoma (KP-B) cell lines. Cells were exposed to X-PACT treatments where the concentrations of drug (psoralen and phosphor) and radiation parameters (energy, dose, and dose rate) were varied. Efficacy was evaluated primarily using flow cell cytometry in combination with complimentary assays, and the in-vivo mouse study. In an in-vitro study, we show that X-PACT induces significant tumor cell apoptosis and cytotoxicity, unlike psoralen or phosphor alone (p<0.0001). We also show that apoptosis increases as doses of phosphor, psoralen, or radiation increase. Finally, in an in-vivo pilot study of BALBc mice with syngeneic 4T1 tumors, we show that the rate of tumor growth is slower with X-PACT than with saline or AMT + X-ray (p<0.0001). Overall these studies demonstrate a potential therapeutic effect for X-PACT, and provide a foundation and rationale for future studies. In summary, X-PACT represents a novel treatment approach in which well-tolerated low doses of x-ray radiation are delivered to a specific tumor site to generate UVA light which

  8. X-Ray Psoralen Activated Cancer Therapy (X-PACT)

    PubMed Central

    Oldham, Mark; Yoon, Paul; Fathi, Zak; Beyer, Wayne F.; Adamson, Justus; Liu, Leihua; Alcorta, David; Xia, Wenle; Osada, Takuya; Liu, Congxiao; Yang, Xiao Y.; Dodd, Rebecca D.; Herndon, James E.; Meng, Boyu; Kirsch, David G.; Lyerly, H. Kim; Dewhirst, Mark W.; Fecci, Peter; Walder, Harold; Spector, Neil L.

    2016-01-01

    This work investigates X-PACT (X-ray Psoralen Activated Cancer Therapy): a new approach for the treatment of solid cancer. X-PACT utilizes psoralen, a potent anti-cancer therapeutic with current application to proliferative disease and extracorporeal photopheresis (ECP) of cutaneous T Cell Lymphoma. An immunogenic role for light-activated psoralen has been reported, contributing to long-term clinical responses. Psoralen therapies have to-date been limited to superficial or extracorporeal scenarios due to the requirement for psoralen activation by UVA light, which has limited penetration in tissue. X-PACT solves this challenge by activating psoralen with UV light emitted from novel non-tethered phosphors (co-incubated with psoralen) that absorb x-rays and re-radiate (phosphoresce) at UV wavelengths. The efficacy of X-PACT was evaluated in both in-vitro and in-vivo settings. In-vitro studies utilized breast (4T1), glioma (CT2A) and sarcoma (KP-B) cell lines. Cells were exposed to X-PACT treatments where the concentrations of drug (psoralen and phosphor) and radiation parameters (energy, dose, and dose rate) were varied. Efficacy was evaluated primarily using flow cell cytometry in combination with complimentary assays, and the in-vivo mouse study. In an in-vitro study, we show that X-PACT induces significant tumor cell apoptosis and cytotoxicity, unlike psoralen or phosphor alone (p<0.0001). We also show that apoptosis increases as doses of phosphor, psoralen, or radiation increase. Finally, in an in-vivo pilot study of BALBc mice with syngeneic 4T1 tumors, we show that the rate of tumor growth is slower with X-PACT than with saline or AMT + X-ray (p<0.0001). Overall these studies demonstrate a potential therapeutic effect for X-PACT, and provide a foundation and rationale for future studies. In summary, X-PACT represents a novel treatment approach in which well-tolerated low doses of x-ray radiation are delivered to a specific tumor site to generate UVA light which

  9. Rapid X-Ray Variability of Active Galaxies. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Tennant, A. F., Jr.

    1983-01-01

    Active galactic nuclei are luminous sources of X-rays. The thesis that the X-rays are generated within 10 gravitational radii from the central object is tested. A very sensitive search for rapid ( 1 day) X-ray variability from active galaxies was made.

  10. Development of x-ray multilayer telescope optics for XTP mission

    NASA Astrophysics Data System (ADS)

    Shen, Zhengxiang; Wang, Xiaoqiang; Wang, Kun; Ma, Bin; Huang, Qiushi; Zhang, Zhong; Wang, Haifeng; Dai, Ying; He, Pengfei; Wang, Zhanshan

    2016-07-01

    The X-ray Timing and Polarization (XTP) satellite is dedicated to study black hole, neutron star and magnetar and then get more information in the physics under extreme gravity, density and magnetism. With an effective area of about 1 square meter and angular resolution of 1 arcminute, XTP is expected to make the most sensitive temporal and polarization observations with good energy resolution in 1-30 keV. Large collecting areas are obtained by tightly nesting layers of grazing incidence mirrors in a conical approximation Wolter-I design. The segmented mirrors that form these layers are formed by thermally slumping glass substrates coated with depth-graded W/Si multilayers for enhanced reflectivity in higher energy region. In order to force the overall shape of the nominally cylindrical substrates to the appropriate conic form, an over-constraint method was used to assemble the mirrors to a telescope. We will present performance on the XTP optics and report the current status of the telescope.

  11. Analytical computation of stray light in nested mirror modules for x-ray telescopes

    NASA Astrophysics Data System (ADS)

    Spiga, Daniele

    2015-09-01

    Stray light in X-ray telescopes are a well-known issue. Unlike rays focused via a double reflection by usual grazing-incidence geometries such as the Wolter-I, stray rays coming from off-axis sources are reflected only once by either the parabolic or the hyperbolic segment. Although not focused, stray light may represent a major source of background and ghost images especially when observing a field of faint sources in the vicinities of another, more intense, just outside the field of view of the telescope. The stray light problem is faced by mounting a pre-collimator in front of the mirror module, in order to shade a part of the reflective surfaces that may give rise to singly-reflected rays. Studying the expected stray light impact, and consequently designing a pre-collimator, is a typical ray-tracing problem, usually time and computation consuming, especially if we consider that rays propagate throughout a densely nested structure. This in turn requires one to pay attention to all the possible obstructions, increasing the complexity of the simulation. In contrast, approaching the problems of stray light calculation from an analytical viewpoint largely simplifies the problem, and may also ease the task of designing an effective pre-collimator. In this work we expose an analytical formalism that can be used to compute the stray light in a nested optical module in a fast and effective way, accounting for obstruction effects.

  12. Measurement of the point spread function and effective area of the Solar-A Soft X-ray Telescope mirror

    NASA Technical Reports Server (NTRS)

    Lemen, J. R.; Claflin, E. S.; Brown, W. A.; Bruner, M. E.; Catura, R. C.

    1989-01-01

    A grazing incidence solar X-ray telescope, Soft X-ray Telescope (SXT), will be flown on the Solar-A satellite in 1991. Measurements have been conducted to determine the focal length, Point Spread Function (PSF), and effective area of the SXT mirror. The measurements were made with pinholes, knife edges, a CCD, and a proportional counter. The results show the 1/r character of the PSF, and indicate a half power diameter of 4.9 arcsec and an effective area of 1.33 sq cm at 13.3 A (0.93 keV). The mirror was found to provide a high contrast image with very little X-ray scattering.

  13. X-ray and optical performance of the flight filters for the JET-X telescope

    NASA Astrophysics Data System (ADS)

    Castelli, Christian M.; Watson, D. J.; Wells, Alan A.; Kent, Barry J.; Barbera, Marco; Collura, Alfonso; Bavdaz, Marcos

    1997-10-01

    The optical filters on board the JET-X telescope comprise thin foils of aluminum coated Lexan. During ground calibration of the filters, narrow spectral regions of high UV leakage, with peak levels of up to a few percent, were observed in broad band optical measurements in the 1000 to 10,000 angstrom range. Furthermore, transmission values were typically up to two orders of magnitude higher than calculated for the aluminum thickness. Investigation showed that these effects were attributed to a combination of aluminum oxidation, which reduces the opacity, and the use of a double sided aluminum layer in the filter design which behaves as a Fabry-Perot interference filter. These effects were verified by a multi- layer model of the filter UV response. Recent redesign of the filters for the flight program eliminated the UV leakage by adopting a single aluminum layer configuration, thus eliminating interference effects, and increasing the thickness by 30% to compensate for oxidation levels. The integrated x- ray transmission below 1 keV was found to be only reduced by 3%. In parallel with the production of the new Lexan flight filters, a set of qualification model filters was produced by the Luxel Corporation in the USA. These filters use polyimide as a substrate material which has the advantage that it is optically opaque to wavelengths below 3000 angstroms, unlike Lexan which is transparent. These new filters were found to have superior mechanical strength, being able to survive extended qualification vibration without any visible degradation in performance, and had a higher cosmetic quality and attenuation levels. As a result, these filters have now been included in the JET-X flight program. We report on the optical tests results from both Lexan and polyimide filters along with high resolution x-ray transmission results carried out at the BESSY synchrotron facility in Germany. Results of the mapping of the filter edge structures, global transmission values and

  14. Point spread function of ASTRO-H Soft X-ray Telescope (SXT)

    NASA Astrophysics Data System (ADS)

    Hayashi, Takayuki; Sato, Toshiki; Kikuchi, Naomichi; Iizuka, Ryo; Maeda, Yoshitomo; Ishida, Manabu; Kurashima, Sho; Nakaniwa, Nozomi; Okajima, Takashi; Mori, Hideyuki; Soong, Yang; Serlemitsos, Peter J.

    2016-07-01

    ASTRO-H (Hitomi) satellite equips two Soft X-ray Telescopes (SXTs), one of which (SXT-S) is coupled to Soft X-ray Spectrometer (SXS) while the other (SXT-I) is coupled to Soft X-ray Imager (SXI). Although SXTs are lightweight of 42 kgmodule-1 and have large on-axis effective area (EA) of 450 cm2 at 4.5 keV module-1 by themselves, their angular resolutions are moderate 1.2 arcmin in half power diameter. The amount of contamination into the SXS FOV (3.05 x 3.05 arcmin2) from nearby sources was measured in the ground-based calibration at the beamline in Institute of Space and Astronautical Science. The contamination at 4.5 keV were measured with sources distant from the SXS center by one width of the FOV in perpendicular and diagonal directions, that is, 3 and 4.5 arcmin-off, respectively. The average EA of the contamination in the four directions with the 3 and 4.5 arcmin-off were measured to be 2 and 0.6% of the on-axis EA of 412 cm2 for the SXS FOV, respectively. The contamination from a source distant by two FOV widths in a diagonal direction, that is, 8.6 arcmin-off was measured to be 0.1% of the on-axis at 4.5 keV. The contamination amounts were also measured at 1.5 keV and 8.0 keV which indicated that the ratio of the contamination EA to that of on-axis hardly depended on the source energy. The off-axis SXT-I images from -4.5 to 27 arcmin were acquired at intervals of 4.5 arcmin for the SXI FOV of 38 x 38 arcmin2. The image shrinked as the off-axis angle increased. Above 13.5 arcmin of off-angle, a stray appeared around the image center in the off-axis direction. As for the on-axis image, a ring-shaped stray appeared at the edge of SXI of 18 arcmin distant from the image center.

  15. Active x-ray optics for Generation-X, the next high resolution x-ray observatory

    NASA Astrophysics Data System (ADS)

    Elvis, Martin; Brissenden, R. J.; Fabbiano, G.; Schwartz, D. A.; Reid, P.; Podgorski, W.; Eisenhower, M.; Juda, M.; Phillips, J.; Cohen, L.; Wolk, S.

    2006-06-01

    X-rays provide one of the few bands through which we can study the epoch of reionization, when the first galaxies, black holes and stars were born. To reach the sensitivity required to image these first discrete objects in the universe needs a major advance in X-ray optics. Generation-X (Gen-X) is currently the only X-ray astronomy mission concept that addresses this goal. Gen-X aims to improve substantially on the Chandra angular resolution and to do so with substantially larger effective area. These two goals can only be met if a mirror technology can be developed that yields high angular resolution at much lower mass/unit area than the Chandra optics, matching that of Constellation-X (Con-X). We describe an approach to this goal based on active X-ray optics that correct the mid-frequency departures from an ideal Wolter optic on-orbit. We concentrate on the problems of sensing figure errors, calculating the corrections required, and applying those corrections. The time needed to make this in-flight calibration is reasonable. A laboratory version of these optics has already been developed by others and is successfully operating at synchrotron light sources. With only a moderate investment in these optics the goals of Gen-X resolution can be realized.

  16. SPECTRAL SURVEY OF X-RAY BRIGHT ACTIVE GALACTIC NUCLEI FROM THE ROSSI X-RAY TIMING EXPLORER

    SciTech Connect

    Rivers, Elizabeth; Markowitz, Alex; Rothschild, Richard

    2011-03-15

    Using long-term monitoring data from the Rossi X-ray Timing Explorer (RXTE), we have selected 23 active galactic nuclei (AGNs) with sufficient brightness and overall observation time to derive broadband X-ray spectra from 3 to {approx}>100 keV. Our sample includes mainly radio-quiet Seyferts, as well as seven radio-loud sources. Given the longevity of the RXTE mission, the greater part of our data is spread out over more than a decade, providing truly long-term average spectra and eliminating inconsistencies arising from variability. We present long-term average values of absorption, Fe line parameters, Compton reflection strengths, and photon indices, as well as fluxes and luminosities for the hard and very hard energy bands, 2-10 keV and 20-100 keV, respectively. We find tentative evidence for high-energy rollovers in three of our objects. We improve upon previous surveys of the very hard X-ray energy band in terms of accuracy and sensitivity, particularly with respect to confirming and quantifying the Compton reflection component. This survey is meant to provide a baseline for future analysis with respect to the long-term averages for these sources and to cement the legacy of RXTE, and especially its High Energy X-ray Timing Experiment, as a contributor to AGN spectral science.

  17. High resolution imaging with multilayer soft X-ray, EUV and FUV telescopes of modest aperture and cost

    NASA Technical Reports Server (NTRS)

    Walker, Arthur B. C., Jr.; Lindblom, Joakim F.; Timothy, J. G.; Hoover, Richard B.; Barbee, Troy W., Jr.; Baker, Phillip C.; Powell, Forbes R.

    1991-01-01

    The development of multilayer reflective coatings now permits soft X-ray, EUV and FUV radiation to be efficiently imaged by conventional normal incidence optical configurations. Telescopes with quite modest apertures can, in principle, achieve images with resolutions which would require apertures of 1.25 meters or more at visible wavelengths. The progress is reviewed which has been made in developing compact telescopes for ultra-high resolution imaging of the sun at soft X-ray, EUV and FUV wavelengths, including laboratory test results and astronomical images obtained with rocket-borne multilayer telescopes. The factors are discussed which limit the resolution which has been achieved so far, and the problems which must be addressed to attain, and surpass the 0.1 arc-second level. The application of these technologies to the development of solar telescopes for future space missions is also described.

  18. Optical activity of the high-mass X-ray binary SAX J2103.5+4545.

    NASA Astrophysics Data System (ADS)

    Grishina, T. S.; Larionova, E. G.; Savchenko, S. S.; Larionov, V. M.

    2017-03-01

    We report on the renewed optical activity of the high-mass X-ray binary system SAX J2103.5+4545. The source is monitored with the 0.4-m LX-200 (St.Petersburg, Russia) and 0.7-m AZT-8 (CrAO, Russia) telescopes.

  19. The Active Galactic Nuclei Population through the eyes of X-ray surveys

    NASA Astrophysics Data System (ADS)

    Civano, Francesca M.

    2015-08-01

    For more than 30 years, X-ray surveys have provided a unique and powerful tool to find and study accreting super- massive black holes (SMBHs) in the distant Universe. In the past decade alone, dozens of surveys in the 0.5-10 keV band with XMM-Newton and Chandra have covered a wide range in area and X-ray flux, corresponding to a similarly wide range in luminosity and redshift. The luminosity function of Active Galactic Nuclei (AGN) has thus been sampled over three decades or more in X-ray luminosity and up to redshifts z=5, defining the evolution of unobscured and obscured (up to column densities of 1023 cm-2) sources and reaching fainter luminosities than optical surveys. The advent of the NuSTAR telescope, with its 3-20 keV energy range, allows us to now complement the "soft" surveys, providing the ability to characterize the whole population, including highly obscured sources.Moreover, the availability of extremely deep multiwavelength data (from radio to UV) for most of the X-ray surveys allows a full understanding of the relationship between the nuclear engine and its host up to very high redshift, not only when the engine is obscured but also when it is bright and shining.In this talk, I will present the XMM-Newton, Chandra and NuSTAR surveys in the 2deg2 of the COSMOS field, focusing on new results from the 4.6 Ms Chandra COSMOS Legacy survey. This new sample includes more than 4000 X-ray detected sources with multiwavelength information, including photometric redshifts for 97% of the sample, and a spectroscopic completeness of 40%. I will present the properties of the detected Chandra sources, in particular those at high redshift, and I will highlight the connection to the NuSTAR detected ones, including the discovery of a new Compton Thick AGN.

  20. Toward a Complete Metrological Solution for the Mirrors for the Constellation-X Spectroscopy X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Lehan, John; Owens, S.; Hadjimichael, T.; Hong, M.; Chan, K.-W.; Saha, T. T.; Reid, P.; Zhang, W. W.

    2007-01-01

    We present an overview update of the metrological approach to be employed for the segmented mirror fabrication for Constellation-X spectroscopy x-ray telescope. We compare results achieved to date with mission requirements. This is discussed in terms of inherent capability versus in-practice capability.

  1. Technology Requirements for a Square Meter, Arcsecond Resolution Telescope for X-Rays: The SMART-X Mission

    NASA Technical Reports Server (NTRS)

    Schwartz, Daniel A.; Allured, Ryan; Bookbinder, Jay A.; Cotroneo, Vincenzo; Forman, William R.; Freeman, Mark D.; McMuldroch, Stuart; Reid, Paul B.; Tananbaum, Harvey; Vikhlinin, Alexey A.; Johnson-Wilke, Raegan L.; Trolier-McKinstry, Susan E.; Wilke, Rudeger H. T.; Jackson, Thomas N.; Ramirez, J. Israel; Gubarev, Mikhail V.; Kolodziejczak, Jeffery J.; ODell, Stephen L.; Ramsey, Brian D.

    2014-01-01

    Addressing the astrophysical problems of the 2020's requires sub-arcsecond x-ray imaging with square meter effective area. Such requirements can be derived, for example, by considering deep x-ray surveys to find the young black holes in the early universe (large redshifts) which will grow into the first super-massive black holes. We have envisioned a mission, the Square Meter Arcsecond Resolution Telescope for X-rays (SMART-X), based on adjustable x-ray optics technology, incorporating mirrors with the required small ratio of mass to collecting area. We are pursuing technology which achieves sub-arcsecond resolution by on-orbit adjustment via thin film piezoelectric "cells" deposited directly on the non-reflecting sides of thin, slumped glass. While SMART-X will also incorporate state-of-the-art x-ray cameras, the remaining spacecraft systems have no requirements more stringent than those which are well understood and proven on the current Chandra X-ray Observatory.

  2. An application of active optics to x-ray imaging: X-mas (x-ray milli arc-second) Project

    NASA Astrophysics Data System (ADS)

    Tsujimoto, Masahiro; Kitamoto, Shunji; Ohkubo, Yohsuke; Sato, Jun'ichi; Watanabe, Takeshi; Sudoh, Keisuke; Sekiguchi, Akiko; Suga, Kazuharu; Sekiguchi, Hiroyuki

    2006-06-01

    We report the current status of the "X-mas" (X-ray milli-arcsecond) project. X-mas is an application of the AO technology to the X-ray optics, aiming to obtain high-resolution defraction-limited X-ray images. Our X-ray telescope employs the Newton optics with a paraboloid primary and a 31-element deformable secondary mirrors. The aperture of the primary mirror is 80 millimeters with the focal length of 2 meters. Multi-layer coating of the mirrors by silicon and molybdenum realizes a large reflectivity of ~60% for the primary and 30-50% for the secondary mirror at 13.5 nm, which enables us to construct a normal incidence optics at this wavelength. We use a laser guide source and a wave front sensor to optimize the form of the secondary deformable mirror for the purpose of offsetting the large-scale figure errors in the X-ray optics. A back-side illumination X-ray CCD detector manufactured by Hamamatsu Photonics is used for X-ray detections. We have assembled all these elements and started to accumulate data. Closed-loop AO is in operation for the laser guide source. Likely X-ray images are obtained through the telescope. The results in 2005-2006 are presented.

  3. Reflectivity around the gold L-edges of x-ray reflector of the soft x-ray telescope onboard ASTRO-H

    NASA Astrophysics Data System (ADS)

    Maeda, Yoshitomo; Kikuchi, Naomichi; Kurashima, Sho; Ishida, Manabu; Iizuka, Ryo; Hayashi, Takayuki; Okajima, Takashi; Matsumoto, Hironori; Mitsuishi, Ikuyuki; Saji, Shigetaka; Sato, Toshiki; Tachibana, Sasagu; Mori, Hideyuki; Christensen, Finn; Brejnholt, Nicolai; Nitta, Kiyofumi; Uruga, Tomoya

    2016-07-01

    We report the atomic scattering factor in the 11.2{15.4 keV for the ASTRO-H Soft X-ray Telescope (SXT)9 obtained in the ground based measurements. The large effective area of the SXT covers above 10 keV. In fact, the flight data show the spectra of the celestical objects in the hard X-ray band. In order to model the area, the reflectivity measurements in the 11.2{15.4 keV band with the energy pitch of 0.4 { 0.7 eV were made in the synchrotron beamline Spring-8 BL01B1. We obtained atomic scattering factors f1 and f2 by the curve fitting to the reflectivities of our witness sample. The edges associated with the gold's L-I, II, and III transitions are identified, of which the depths are found to be roughly 60% shallower than those expected from the Henke's atomic scattering factor.

  4. X-rays and Gamma-rays from active galaxies

    NASA Technical Reports Server (NTRS)

    Matteson, J. L.

    1983-01-01

    Photon-photon pair production in active galaxies is considered, and the concept of the annihilation efficiency, the efficiency of the conversion of continuum luminosity of greater than 511 keV into positron annihilation luminosity, is introduced. Equations that give the source's annihilation luminosity and 511-keV flux as a function of its size, continuum luminosity and distance are developed. These are applied to the available X-ray and gamma-ray data on active galaxies in order to make specific predictions. Efficiencies as high as over 6 percent and fluxes up to 0.0008 ph/sq cm s result. While the latter are below present limits, they are within the reach of advanced instruments now in development.

  5. Reflectivity around the gold M-edges of x-ray reflector of the Soft X-ray Telescope onboard ASTRO-H

    NASA Astrophysics Data System (ADS)

    Kurashima, Sho; Furuzawa, Akihiro; Sato, Toshiki; Kikuchi, Naomichi; Nakaniwa, Nozomi; Maeda, Yoshitomo; Ishida, Manabu; Iizuka, Ryo; Okajima, Takashi; Mori, Hideyuki; Matsumoto, Hironori; Tamura, Keisuke; Ishibashi, Kazunori; Hayashi, Takayuki; Miyazawa, Takuya; Maejima, Masato; Yoshikawa, Shun

    2016-07-01

    The X-ray astronomy satellite ASTRO-H are equipped with two equivalent soft X-ray telescopes (SXT-I and SXT-S) which cover the energy band 0.3{12 keV. The X-ray reflectors of the SXTs are coated with a gold monolayer by means of the replication technique (Okajima et al. in this volume). A series of gold M absorption edges in the 2-4 keV band causes complex structures in the energy response of the SXTs. In the same band, there are astrophysically important emission lines from Si, Ar and S. Since the SXS has unprecedentedly high spectral resolution, we have measured the reflectivity around the gold M-edges in an extremely fine energy pitch at the synchrotron radiation facility KEK PF BL11-B, with the 2 eV pitch in 2100 eV to 4100 eV band that covers the entire series of the absorption edges (M-I through M-V) at grazing incident angles to the reflectors of 0.5, 0.8, 1.0, 1.2, 1.4 degree, and with a finer pitch of 0.25 eV in the 2200 eV to 2350 eV band where the two deepest M-IV and M-V edges are included. In the resultant reflectivity curves, we have clearly identified the fine structures associated with all the M-edges. Using these data, we calculated atomic scattering factor f1 as a function of X-ray energy, with which we have built the mirror response function which can be applied to the Suzaku spectra. As a result, we have found that discrepancy of the spectral model to the Suzaku data of 4U1630-472 (a black hole transient) and the Crab nebula around the M-edges are significantly reduced from those with the official Suzaku response.

  6. Optics for X-ray telescopes: analytical treatment of the off-axis effective area of mirrors in optical modules

    NASA Astrophysics Data System (ADS)

    Spiga, D.

    2011-05-01

    Context. Optical modules for X-ray telescopes comprise several double-reflection mirrors operating in grazing incidence. The concentration power of an optical module, which determines primarily the telescope's sensitivity, is in general expressed by its on-axis effective area as a function of the X-ray energy. Nevertheless, the effective area of X-ray mirrors in general decreases as the source moves off-axis, with a consequent loss of sensitivity. To make matters worse, the dense nesting of mirror shells in an optical module results in a mutual obstruction of their aperture when an astronomical source is off-axis, with a further effective area reduction. Aims: To ensure the performance of X-ray optics for new X-ray telescopes (like NuSTAR, NHXM, ASTRO-H, IXO), their design entails a detailed computation of the effective area over all the telescope's field of view. While the effective area of an X-ray mirror is easy to predict on-axis, the same task becomes more difficult for a source off-axis. It is therefore important to develop an appropriate formalism to reliably compute the off-axis effective area of a Wolter-I mirror, including the effect of obstructions. Methods: Most of collecting area simulation for X-ray optical modules has been so far performed along with numerical codes, involving ray-tracing routines, very effective but in general complex, difficult to handle, time consuming and affected by statistical errors. In contrast, in a previous paper we approached this problem from an analytical viewpoint, to the end of simplifying and speeding up the prediction of the off-axis effective area of unobstructed X-ray mirrors with any reflective coating, including multilayers. Results: In this work we extend the analytical results obtained: we show that the analytical formula for the off-axis effective area can be inverted, and we expose in detail a novel analytical treatment of mutual shell obstruction in densely nested mirror assemblies, which reduces the off

  7. ISS-Lobster: A Proposed Wide-Field X-Ray Telescope on the International Space Station

    NASA Technical Reports Server (NTRS)

    Camp, Jordan

    2012-01-01

    The Lobster wide-field imaging telescope combines simultaneous high FOV, high sensitivity and good position resolution. These characteristics can open the field of X-Ray time domain astronomy, which will study many interesting transient sources, including tidal disruptions of stars, supernova shock breakouts, and high redshift gamma-ray bursts. Also important will be its use for the X-ray follow-up of gravitational wave detections. I will describe our present effort to propose the Lobster concept for deployment on the International Space Station through a NASA Mission of Opportunity this fall.

  8. Mechanical and Thermal Analysis of the Spectroscopy X-ray Telescopes for the Constellation-X Mission

    NASA Technical Reports Server (NTRS)

    Chan, Kai-Wing; Bolognese, Jeffrey; Saha, Timo; Sturm, James; Zhang, William

    2007-01-01

    Area and mass requirements for the Constellation-X Spectroscopy X-Ray Telescopes restrict the thickness of the mirror segment to below a mm. Requirement of angular resolution of 15" over the soft x-ray band implies that allowable optic deformation is sub-micrometer for these thin segments. These requirements place stringent constraint on the mounting, alignment and affixing of these mirror segments in both the metrology and integration processes. We present analyses and optimization of the Constellation-X mirrors under relevant mechanical and thermal environments.

  9. Electroformed grazing incidence X-ray mirrors for a mirror array telescope

    NASA Technical Reports Server (NTRS)

    Ulmer, Melville P.; Matsui, Yutaka; Bedford, D. K.; Simnett, G. M.; Takacs, Peter Z.

    1987-01-01

    Grazing incidence Wolter type I mirrors for higher-energy X-rays have been replicated from two superpolished mandrels by electroforming. Single mirrors and a nested pair were tested with 1.5- and 6.4-keV X-rays, and their subminute of arc resolution and reflectivity close to the theoretical values are confirmed. The design of the mandrels, the mirror mounting scheme, and results of the X-ray test are presented. The microroughnesses of the mirrors measured using an optical profilometer were compared with the X-ray test results.

  10. The point spread function of the soft X-ray telescope aboard Yohkoh

    NASA Technical Reports Server (NTRS)

    Martens, Petrus C.; Acton, Loren W.; Lemen, James R.

    1995-01-01

    The point spread function of the SXT telescope aboard Yohkoh has been measured in flight configuration in three different X-ray lines at White Sands Missile Range. We have fitted these data with an elliptical generalization of the Moffat function. Our fitting method consists of chi squared minimization in Fourier space, especially designed for matching of sharply peaked functions. We find excellent fits with a reduced chi squared of order unity or less for single exposure point spread functions over most of the CCD. Near the edges of the CCD the fits are less accurate due to vignetting. From fitting results with summation of multiple exposures we find a systematic error in the fitting function of the order of 3% near the peak of the point spread function, which is close to the photon noise for typical SXT images in orbit. We find that the full width to half maximum and fitting parameters vary significantly with CCD location. However, we also find that point spread functions measured at the same location are consistent to one another within the limit determined by photon noise. A 'best' analytical fit to the PSF as function of position on the CCD is derived for use in SXT image enhancemnent routines. As an aside result we have found that SXT can determine the location of point sources to about a quarter of a 2.54 arc sec pixel.

  11. Temperature dependent calibration products of the SWIFT x-ray telescope

    NASA Astrophysics Data System (ADS)

    Morris, David C.; Burrows, David N.; Hill, Joanne E.; Kennea, Jamie; Racusin, Judith; Wood, Paul; Mangels, Chris; Klar, Robert; Angelini, Lorella; Tamburelli, Francesca

    2005-08-01

    The X-Ray Telescope (XRT) on board the Swift satellite is a sensitive imaging spectrometer utilizing a MAT-22 CCD at the Focal plane. The system was designed to operate the CCD at -100 °C +/- 1 °C for the duration of the mission. Due to a failure of the temperature control sub-system, the CCD operates under variable thermal conditions dictated by the view factor of the radiator- heatpipe sub-system to the Earth and sun. A temperature variation of up to 5° C is seen during a single orbit due to the satellite transition from sun light into eclipse and the full operational regime of the instrument ranges from temperatures of -75°C to -45°C due to the persistent heating/cooling effects of satellite orientation to the sun and earth. To maintain the highest quality data products possible from the XRT data stream, a recalibration of the XRT is required to account for this variable thermal environment. We present the methodology for and results from a temperature dependent analysis of on-orbit XRT data, collected during the Swift commissioning phase, used to produce gain, bias and warm pixel calibration products. We also discuss the quality of XRT science products capable with these temperature dependent calibration files and future plans for updates to these calibration products.

  12. Temperature dependent calibration products of the SWIFT x-ray telescope

    NASA Astrophysics Data System (ADS)

    Morris, David C.; Burrows, David N.; Hill, Joanne E.; Kennea, Jamie; Racusin, Judith; Wood, Paul; Mangels, Chris; Klar, Robert; Angelini, Lorella; Tamburelli, Francesca

    2005-01-01

    The X-Ray Telescope (XRT) on board the Swift satellite is a sensitive imaging spectrometer utilizing a MAT-22 CCD at the Focal plane. The system was designed to operate the CCD at -100 °C +/- 1 °C for the duration of the mission. Due to a failure of the temperature control sub-system, the CCD operates under variable thermal conditions dictated by the view factor of the radiator- heatpipe sub-system to the Earth and sun. A temperature variation of up to 5° C is seen during a single orbit due to the satellite transition from sun light into eclipse and the full operational regime of the instrument ranges from temperatures of -75°C to -45°C due to the persistent heating/cooling effects of satellite orientation to the sun and earth. To maintain the highest quality data products possible from the XRT data stream, a recalibration of the XRT is required to account for this variable thermal environment. We present the methodology for and results from a temperature dependent analysis of on-orbit XRT data, collected during the Swift commissioning phase, used to produce gain, bias and warm pixel calibration products. We also discuss the quality of XRT science products capable with these temperature dependent calibration files and future plans for updates to these calibration products.

  13. Research with Large Area Imaging X-Ray Telescope Sounding Rocket Program

    NASA Technical Reports Server (NTRS)

    Gorenstein, Paul

    1999-01-01

    We are engaged in a program to develop focussing hard X-ray telescopes in a double conical or Wolter 1 geometry that function up to 100 keV by employing small graze angles and multilayer coatings. Directly polished substrates are not an option because they are too thick to be nested efficiently. The only alternative is to fabricate the very thin substrates by replication. Our objective is the production of integral cylindrical substrates because they should result in better angular resolution than segmented foil geometries. In addition, integral cylinders would be more resistant to possible stress from deep multilayer coatings than segmented ones. Both electroforming of nickel (method of SkX, JET-X, and XMM) and epoxy replication are under consideration. Both processes can utilize the same types of mandrels and separation agents- While electroforming can produce substrates that are thin, the high density of the nickel may result in high weight optics for some missions. For convenience, experimentation with replication and coating is being carried out initially on flats. Our replication studies include trials with gold and carbon separation agents. This paper reports on our efforts with epoxy replicated optics.

  14. The impact of the in-orbit background and the X-ray source intensity on the centroiding accuracy of the Swift X-ray telescope

    NASA Astrophysics Data System (ADS)

    Ambrosi, R. M.; Hutchinson, I. B.; Hill, J.; Cheruvu, C.; Abbey, A. F.; Short, A. D. T.

    2002-11-01

    The optical components of the Swift Gamma Ray Burst Explorer X-ray Telescope (XRT), consisting of the JET-X spare flight mirror and a charge coupled device of the type used in the EPIC program, were used in a re-calibration study carried out at the Panter facility, which is part of the Max Plank Institute for Extraterrestrial Physics. The objective of this study was to check the focal length and the off axis performance of the mirrors and to show that the half energy width (HEW) of the on-axis point spread function (PSF) was of the order of 16arcsec at 1.5keV (Nucl. Instr. and Meth. A 488 (2002) 543; SPIE 4140 (2000) 64) and that a centroiding accuracy better that 1arcsec could be achieved within the 4arcmin sampling area designated by the Burst Alert Telescope (Nucl. Instr. and Meth. A 488 (2002) 543). The centroiding accuracy of the Swift XRT's optical components was tested as a function of distance from the focus and off axis position of the PSF (Nucl. Instr. and Meth. A 488 (2002) 543). The presence of background events in the image frame introduced errors in the centroiding process, making the choice of centroiding algorithm important (Nucl. Instr. and Meth. A 488 (2002) 543). Since the objective of Swift is to rapidly investigate the X-ray afterglows of Gamma Ray Bursts the possibility of detecting a bright source with intensity greater than 25 Crab could not be excluded and therefore the impact of a saturated PSF core on the centroiding accuracy was investigated by experimental methods.

  15. Development of a Prototype Nickel Optic for the Constellation-X Hard-X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    Basso, S.; Bruni, R. J.; Citerio, O.; Engelhaupt, D.; Ghigo, M.; Gorenstien, P.; Mazzoleni, F.; ODell, S. L.; Pareschi, G.; Ramsey, B. D.

    2003-01-01

    The Constellation-X mission, planned for launch in 2011, will feature an array of hard-x ray telescopes with a total collecting area goal of 1500 square centimeters at 40 keV. Various technologies are currently being investigated for the optics of these telescopes including multilayer-coated Eletroformed-Nickel-Replicated (ENR) shells. The attraction of the ENR process is that the resulting full-shell optics are inherently stable and offer the promise of good angular resolution and enhanced instrument sensitivity. The challenge for this process is to meet a relatively tight weight budget with a relatively dense material (rho nickel = 9 grams per cubic centimeters.) To demonstrate the viability of the ENR process we are fabricating a prototype HXT mirror module to be tested against a competing segmented-glass-shell optic. The ENR prototype will consist of 5 shells of diameters from 150 mm to 280 mm and of 426 mm total length. To meet the stringent weight budget for Con-X, the shells will be only 150 micron thick. The innermost of these will be coated with Iridium, while the remainder will be coated with graded-density multilayers. Mandrels for these shells are currently under fabrication (Jan 03), with the first shells scheduled for production in February 03. A tentative date of late Summer has been set for prototype testing. Issues currently being addressed are the control of stresses in the multiplayer coating and ways of mitigating their effects on the figure of the necessarily thin shells. Also, the fabrication, handling and mounting of these shells without inducing permanent figure distortions. A full status report on the prototype optic will be presented along with test results as available.

  16. ESA's X-ray space telescope proves supernovae can cause mysterious gamma-ray bursts

    NASA Astrophysics Data System (ADS)

    2002-04-01

    By analysing the afterglow of the gamma-ray burst in the X-ray light, scientists produced the first ever evidence of the presence of chemical elements which were the unmistakable remnants of a supernova explosion which had occurred just a few days before. "We can now confidently say that the death of a massive star, a supernova, was the cause of a gamma-ray burst. However we still don't know exactly how and why these bursts, the most energetic phenomena in the Universe, are triggered," says ESA astronomer Norbert Schartel, a co-author of the original paper, published today in Nature. Gamma-ray bursts were first discovered in 1967 by chance, when satellites designed to look for violations of the Nuclear Test Ban Treaty detected strong gamma-ray emissions coming from sources not in the vicinity of Earth, but from outer space. They have been a mystery ever since. They occur as often as several times a day but last for no longer than a couple of minutes, and there is no way to predict when or where the next burst will occur. Consequently they are very difficult to study. For three decades it was not even known whether the explosions were close, in our own Milky Way galaxy, or far away in distant galaxies. But astronomers set up an 'alert system'. This allows them to see the 'afterglow' of the burst before it fades away, by quickly aiming their telescopes at the precise location in the sky shortly after a detector triggers the alert. It is now clear that the bursts occur in galaxies millions of light-years away. The longest burst Technically called 'GRB 011211', it was first detected on 11 December 2001 at 19:09:21 (Universal Time), by the Italian-Dutch satellite BeppoSAX. The burst lasted for 270 seconds - the longest one observed by the satellite. A few hours afterwards, when a first analysis confirmed that a burst had indeed been registered, the BeppoSAX team alerted the rest of the astronomical community. ESA's XMM-Newton arrived on the scene 11 hours after the

  17. Optics Requirements For The Generation-X X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    O'Dell, S. .; Elsner, R. F.; Kolodziejczak, J. J.; Ramsey, B. D.; Weisskopf, M. C.; Zhang, W. W.; Content, D. A.; Petre, R.; Saha, T. T.; Reid, P. B.; Schwartz, D. A.; Brissenden, R. J.; Elvis, M.; Freeman, M.; Gaetz, T.; Gorenstein, P.; Jerius, D.; Juda, M.; Murray, S. S.; Podgorski, W. A.; Wolk, S. J.; Trolier-McKinstry, S.

    2008-01-01

    US, European, and Japanese space agencies each now operate successful X-ray missions -- NASA s Chandra, ESA s XMM-Newton, and JAXA s Suzaku observatories. Recently these agencies began a collaboration to develop the next major X-ray astrophysics facility -- the International X-ray Observatory (IXO) -- for launch around 2020. IXO will provide an order-of-magnitude increase in effective area, while maintaining good (but not sub-arcsecond) angular resolution. X-ray astronomy beyond IXO will require optics with even larger aperture areas and much better angular resolution. We are currently conducting a NASA strategic mission concept study to identify technology issues and to formulate a technology roadmap for a mission -- Generation-X (Gen-X) -- to provide these capabilities. Achieving large X-ray collecting areas in a space observatory requires extremely lightweight mirrors.

  18. A COMBINED LOW-RADIO FREQUENCY/X-RAY STUDY OF GALAXY GROUPS. I. GIANT METREWAVE RADIO TELESCOPE OBSERVATIONS AT 235 MHz AND 610 MHz

    SciTech Connect

    Giacintucci, Simona; O'Sullivan, Ewan; Vrtilek, Jan; David, Laurence P.; Mazzotta, Pasquale; Gitti, Myriam; Jones, Christine; Forman, William R.; Raychaudhury, Somak; Ponman, Trevor; Venturi, Tiziana; Athreya, Ramana M.; Clarke, Tracy E.; Murgia, Matteo; Ishwara-Chandra, C. H.

    2011-05-10

    We present new Giant Metrewave Radio Telescope observations at 235 MHz and 610 MHz of 18 X-ray bright galaxy groups. These observations are part of an extended project, presented here and in future papers, which combines low-frequency radio and X-ray data to investigate the interaction between central active galactic nuclei (AGNs) and the intra-group medium (IGM). The radio images show a very diverse population of group-central radio sources, varying widely in size, power, morphology, and spectral index. Comparison of the radio images with Chandra and XMM-Newton X-ray images shows that groups with significant substructure in the X-ray band and marginal radio emission at {approx}>1 GHz host low-frequency radio structures that correlate with substructures in IGM. Radio-filled X-ray cavities, the most evident form of AGN/IGM interaction in our sample, are found in half of the systems and are typically associated with small, low-, or mid-power double radio sources. Two systems, NGC5044 and NGC4636, possess multiple cavities, which are isotropically distributed around the group center, possibly due to group weather. In other systems the radio/X-ray correlations are less evident. However, the AGN/IGM interaction can manifest itself through the effects of the high-pressure medium on the morphology, spectral properties, and evolution of the radio-emitting plasma. In particular, the IGM can confine fading radio lobes in old/dying radio galaxies and prevent them from dissipating quickly. Evidence for radio emission produced by former outbursts that co-exist with current activity is found in six groups of the sample.

  19. X-ray color analysis of the spectra of active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Netzer, Hagai; Turner, T. J.; George, Ian M.

    1994-01-01

    The identification and detection of X-ray absorption and emission features depends on the resolution and the signal-to-noise ratio (S/N) of the observation, the understanding of the instrument response, and the Galactic line-of-sight absorption. Since many of the active galactic nucleus (AGN) data sets are limited in their S/N and full modeling of the physical conditions is rather complicated, we suggest a new analysis method based on 'X-ray colors.' The two sets of X-ray colors, defined for low (ROSAT Position Sensitive Proportional Counter (PSPC)) and medium (Broad Band X-Ray Telescope (BBXRT)) and ASCA Solid-State Imaging Spectrometers (SIS) resolution experiments, are used to separate regions of different physical conditions in a two-dimensional color-color plane. They are similar but superior to previous methods using the X-ray 'hardness ratio' in being able to reveal more of the physical properties of the source. We illustrate the use of such diagrams by studying a number of AGNs suspected of showing absorption features. A sample of 14 AGNs observed by the ROSAT PSPC is presented which includes several objects with suspected 'warm absorbers' along the line-of-sight to the nucleus, several others exhibiting intrinsic continuum variations, and a number of control objects thought to be featureless. Our new observations show, for the first time, the color variation as a function of time for three of the Seyfert 1 sources: NGC 4051, Mrk 335, and Mrk 766. The variations suggest that in two sources we are witnessing real changes in continuum shape, while one (NGC 4051) is consistent with having a warm absorber. Four of the objects observed by BBXRT are reanalyzed using our X-ray colors. Out of these, we discuss in detail the case of NGC 4151 and show that the color-color analysis agrees very well with previous, detailed spectral fitting methods. In particular, we confirm that the observed BBXRT observation of this source is not consistent with the warm absorber

  20. GSFC Contributions to the NATO X-ray Astronomy Institute, Erice, July 1979. [X-ray spectra of supernova remants, galactic X-ray sources, active galactic nuclei, and clusters of galaxies

    NASA Technical Reports Server (NTRS)

    Holt, S. S.; Mushotzky, R. F.

    1979-01-01

    An overview of X-ray astronomical spectroscopy in general is presented and results obtained by HEAO 1 and 2 as well as earlier spacecraft are examined. Particular emphasis is given to the spectra of supernova remnants; galactic binary X-ray sources, cataclysmic variables, bulges, pulsars, and stars; the active nuclei of Seyfert 1 galaxy, BL Lac, and quasars; the diffuse X-ray background; and galactic clusters.

  1. Fast fluctuations of soft X-rays from active regions

    NASA Technical Reports Server (NTRS)

    Simnett, G. F.; Dennis, B. R.

    1986-01-01

    A selection of short lived small soft X-ray bursts is studied using data from the Hard X-ray Imaging Spectrometer (HXIS), and the results are compared with the data from the Hard X-Ray Burst Spectrometer (HXRBS) with a view to understanding conditions at the onset of flares. Short-lived events provide an opportunity to study the radiation from the primary energy transfer process without confusion from the slowly-varying thermal X-ray emission which characterizes the decay of a large flare. The fast decay of the soft X-rays, only a few tens of seconds, suggests that they occur in the dense chromosphere. The results indicate that the short events may be signatures of several different phenomena, depending on their characteristics. Some events occur in association with reverse-drift type III bursts and simultaneous flaring elsewhere on the Sun, thus suggesting dumping of particles accelerated at a remote site. Some events have hard X-ray bursts and normal type III bursts associated with them, while others have neither. The latter events place strong constraints on the nonthermal electron population present.

  2. X-ray spectral diagnostics of activity in massive stars

    NASA Astrophysics Data System (ADS)

    Cohen, David H.; Wollman, Emma E.; Leutenegger, Maurice A.

    2011-07-01

    X-rays give direct evidence of instabilities, time-variable structure, and shock heating in the winds of O stars. The observed broad X-ray emission lines provide information about the kinematics of shock-heated wind plasma, enabling us to test wind-shock models. And their shapes provide information about wind absorption, and thus about the wind mass-loss rates. Mass-loss rates determined from X-ray line profiles are not sensitive to density-squared clumping effects, and indicate mass-loss rate reductions of factors of 3 to 6 over traditional diagnostics that suffer from density-squared effects. Broad-band X-ray spectral energy distributions also provide mass-loss rate information via soft X-ray absorption signatures. In some cases, the degree of wind absorption is so high, that the hardening of the X-ray SED can be quite significant. We discuss these results as applied to the early O stars ζ Pup (O4 If), 9 Sgr (O4 V((f))), and HD 93129A (O2 If*).

  3. Mathematical Formalism for Designing Wide-Field X-Ray Telescopes: Mirror Nodal Positions and Detector Tilts

    NASA Technical Reports Server (NTRS)

    Elsner, R. F.; O'Dell, S. L.; Ramsey, B. D.; Weisskopf, M. C.

    2011-01-01

    We provide a mathematical formalism for optimizing the mirror nodal positions along the optical axis and the tilt of a commonly employed detector configuration at the focus of a x-ray telescope consisting of nested mirror shells with known mirror surface prescriptions. We adopt the spatial resolution averaged over the field-of-view as the figure of merit M. A more complete description appears in our paper in these proceedings.

  4. Simulations of X-Ray Telescopes for eROSITA and IXO

    SciTech Connect

    Schmid, C.; Wilms, J.; Kreykenbohm, I.; Martin, M.; Kendziorra, E.; Muehlegger, M.; Brunner, H.; Fuermetz, M.; Predehl, P.; Barret, D.

    2010-07-15

    We report on the development of a generic X-ray instrument simulator to be used in simulations of future X-ray missions. Based on a Monte Carlo approach the code generates photon events for sources in an X-ray source catalogue such as the ROSAT all sky survey or the XMM-Newton slew surveys and then models the imaging and detection process based on the available calibration files (e.g., point spread functions for the imaging). The output of the program are event lists, which can be analysed using standard software such as xselect. Due to its modular concept the simulation software can be easily adapted to different concepts of imaging detectors.As examples for the potential use of the simulation we present our studies for eROSITA and show results of simulations of the detector performance for the High Time Resolution Spectrometer and the Wide Field Imager on the International X-ray Observatory.

  5. Activation of oncogenes by radon progeny and x-rays

    SciTech Connect

    Ling, C.C.

    1990-01-01

    The overall goal of this proposal is to study the carcinogenic effect of both high and low LET radiation at the molecular level, utilizing techniques developed in molecular biology, cancer cell biology and radiation biology. The underlying assumption is that malignant transformation of normal cells is a multistep process requiring two or more molecular events in the genomic DNA. We hypothesize that radiation may induce such events in one or more steps of the multistep process. We will use in vitro models of transformation that reproduce the stepwise progression of normal cells toward the transformed phenotype and ask whether radiation can provide the necessary activating function at discrete steps along this path. Our strategy involves transfecting into normal primary cells a variety of cloned oncogenes that are known to supply only some of the functions necessary for full transformation. These partially transformed'' cells will be the targets for irradiation by x-rays and alpha particles. The results will provide the basis for assessing the ability of ionizing radiation to activate oncogenic functions that complement'' the oncogene already present in the transfected cells and produce the fully transformed phenotype. Progress is described. 121 refs.

  6. A normal incidence, high resolution X-ray telescope for solar coronal observations

    NASA Technical Reports Server (NTRS)

    Golub, L.

    1985-01-01

    The following major activities were advanced or completed: complete design of the entire telescope assembly and fabrication of all front-end components; specification of all rocket skin sections including bulkheads, feedthroughs and access door; fabrication, curing, and delivery of the large graphite-epoxy telescope tube; engineering analysis of the primary mirror vibration test was completed and a decision made to redesign the mirror attachment to a kinematic three-point mount; detail design of the camera control, payload and housekeeping electronics; and multilayer mirror flats with 2d spacings of 50 A and 60 A.

  7. Coronal X-ray activity preceding solar flares

    NASA Technical Reports Server (NTRS)

    Webb, D. F.

    1985-01-01

    The characteristics of coronal emplacements preceding solar flares were investigated based on a comprehensive survey of Skylab soft X-ray images. A search interval of 30 min before flare was used in the X-ray observations. X-ray images with preflare enhancements were compared with high resolution H-alpha images and photospheric magnetograms and preflare enhancements were found in a statistically significant number of the observed preflare intervals. The enhancement events consisted of loops, kernels, and sinuous features with one to three separate preflare structures appearing in each interval. Typical gas pressures in the preflare X-ray features were estimated on the order of a few dyne per sq cm and densities were 4-10 x 10 to the -9th per cu cm for assumed average temperatures. H-alpha brightenings in the form of knots and patches were found in conjunction with the X-ray preflare features in nearly all of the intervals. It is concluded that H-alpha emission is characteristic of preflare emission processes. The observational data are interpreted within the framework of existing loop preheating models, and the results are discussed in detail.

  8. Very low luminosity active galaxies and the X-ray background

    NASA Technical Reports Server (NTRS)

    Elvis, M.; Soltan, A.; Keel, W. C.

    1984-01-01

    The properties of very low luminosity active galactic nuclei are not well studied, and, in particular, their possible contribution to the diffuse X-ray background is not known. In the present investigation, an X-ray luminosity function for the range from 10 to the 39th to 10 to the 42.5th ergs/s is constructed. The obtained X-ray luminosity function is integrated to estimate the contribution of these very low luminosity active galaxies to the diffuse X-ray background. The construction of the X-ray luminosity function is based on data obtained by Keel (1983) and some simple assumptions about optical and X-ray properties.

  9. The pre-collimator for the ASTRO-H x-ray telescopes: shielding from stray lights

    NASA Astrophysics Data System (ADS)

    Mori, Hideyuki; Maeda, Yoshitomo; Ishida, Manabu; Sato, Takuro; Ichihara, Kou; Tomikawa, Kazuki; Kunieda, Hideyo; Tawara, Yuzuru; Sugita, Satoshi; Watanabe, Tsuyoshi; Torii, Tatsuharu; Tachibana, Kenji; Awaki, Hisamitsu; Okajima, Takashi; Mochida, Masayuki; Kawabata, Eiji

    2012-09-01

    We report recent progresses on the fabrication of pre-collimators (PCs). The PCs are designed to mitigate stray lights for X-ray telescopes to be onboard ASTRO-H. Each PC consists of cylindrical aluminum shells (blades) wiht varying radii of 60-225 mm, alignment frames to guilde the blade positions, and the bade housing body. The alignment frame and the housing are made of Aluminum 6061 and 7075 alloy, respectively. Heat-forming process is introduced to the production to stabilize the blade shape in orbit. Precise curvature of radius (tolerance of 1mm) and the linearity along with the direction of incident X-rays (P.V. < 20 microns) ensure that the blades do not obscure the telescope aperature. Each PC blade is placed precisely on top of the respective reflector mirror shell to reduce off-axis X-ray photons that leads to a "ghost" image within the detector field of view. In September 2010, the PC design--its height, thickness, and material of blades--was fixed and we produced the engineering model (EM) for the Soft X-ray Telescopes (SXTs). Since then, vibration tests for the EM PC unit are carried out twice, verifying that the PC has sufficient structural strength to withstand severe conditions during its launch. The EM PC is also installed onto the SXT mirror housing fabricated at the NASA's GSFC to validate our PC assembly method without any loss of thetelescope's effective aperture area. Since August 2011, we have been manusfacturing the PC blades for the flight models. We hereby show the manufacturing processes and also results of stray-light measurement without PCs for the SXT EM (obtained at ISAS 30m beamline facility) and the HXT FM (obtained at SPring-8 synchrotron radiation facility).

  10. Superorbital Periodic Modulation in Wind-Accretion High-Mass X-Ray Binaries from Swift Burst Alert Telescope Observations

    NASA Technical Reports Server (NTRS)

    Corbet, Robin H. D.; Krimm, Hans A.

    2013-01-01

    We report the discovery using data from the Swift-Burst Alert Telescope (BAT) of superorbital modulation in the wind-accretion supergiant high-mass X-ray binaries 4U 1909+07 (= X 1908+075), IGR J16418-4532, and IGR J16479-4514. Together with already known superorbital periodicities in 2S 0114+650 and IGR J16493-4348, the systems exhibit a monotonic relationship between superorbital and orbital periods. These systems include both supergiant fast X-ray transients and classical supergiant systems, and have a range of inclination angles. This suggests an underlying physical mechanism which is connected to the orbital period. In addition to these sources with clear detections of superorbital periods, IGR J16393-4643 (= AX J16390.4-4642) is identified as a system that may have superorbital modulation due to the coincidence of low-amplitude peaks in power spectra derived from BAT, Rossi X-Ray Timing Explorer Proportional Counter Array, and International Gamma-Ray Astrophysics Laboratory light curves. 1E 1145.1-6141 may also be worthy of further attention due to the amount of low-frequency modulation of its light curve. However, we find that the presence of superorbital modulation is not a universal feature of wind-accretion supergiant X-ray binaries.

  11. Mirrors for X-ray telescopes: Fresnel diffraction-based computation of point spread functions from metrology

    NASA Astrophysics Data System (ADS)

    Raimondi, L.; Spiga, D.

    2015-01-01

    Context. The imaging sharpness of an X-ray telescope is chiefly determined by the optical quality of its focusing optics, which in turn mostly depends on the shape accuracy and the surface finishing of the grazing-incidence X-ray mirrors that compose the optical modules. To ensure the imaging performance during the mirror manufacturing, a fundamental step is predicting the mirror point spread function (PSF) from the metrology of its surface. Traditionally, the PSF computation in X-rays is assumed to be different depending on whether the surface defects are classified as figure errors or roughness. This classical approach, however, requires setting a boundary between these two asymptotic regimes, which is not known a priori. Aims: The aim of this work is to overcome this limit by providing analytical formulae that are valid at any light wavelength, for computing the PSF of an X-ray mirror shell from the measured longitudinal profiles and the roughness power spectral density, without distinguishing spectral ranges with different treatments. Methods: The method we adopted is based on the Huygens-Fresnel principle for computing the diffracted intensity from measured or modeled profiles. In particular, we have simplified the computation of the surface integral to only one dimension, owing to the grazing incidence that reduces the influence of the azimuthal errors by orders of magnitude. The method can be extended to optical systems with an arbitrary number of reflections - in particular the Wolter-I, which is frequently used in X-ray astronomy - and can be used in both near- and far-field approximation. Finally, it accounts simultaneously for profile, roughness, and aperture diffraction. Results: We describe the formalism with which one can self-consistently compute the PSF of grazing-incidence mirrors, and we show some PSF simulations including the UV band, where the aperture diffraction dominates the PSF, and hard X-rays where the X-ray scattering has a major impact

  12. CdZnTe Image Detectors for Hard-X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    Chen, C. M. Hubert; Cook, Walter R.; Harrison, Fiona A.; Lin, Jiao Y. Y.; Mao, Peter H.; Schindler, Stephen M.

    2005-01-01

    Arrays of CdZnTe photodetectors and associated electronic circuitry have been built and tested in a continuing effort to develop focal-plane image sensor systems for hard-x-ray telescopes. Each array contains 24 by 44 pixels at a pitch of 498 m. The detector designs are optimized to obtain low power demand with high spectral resolution in the photon- energy range of 5 to 100 keV. More precisely, each detector array is a hybrid of a CdZnTe photodetector array and an application-specific integrated circuit (ASIC) containing an array of amplifiers in the same pixel pattern as that of the detectors. The array is fabricated on a single crystal of CdZnTe having dimensions of 23.6 by 12.9 by 2 mm. The detector-array cathode is a monolithic platinum contact. On the anode plane, the contact metal is patterned into the aforementioned pixel array, surrounded by a guard ring that is 1 mm wide on three sides and is 0.1 mm wide on the fourth side so that two such detector arrays can be placed side-by-side to form a roughly square sensor area with minimal dead area between them. Figure 1 shows two anode patterns. One pattern features larger pixel anode contacts, with a 30-m gap between them. The other pattern features smaller pixel anode contacts plus a contact for a shaping electrode in the form of a grid that separates all the pixels. In operation, the grid is held at a potential intermediate between the cathode and anode potentials to steer electric charges toward the anode in order to reduce the loss of charges in the inter-anode gaps. The CdZnTe photodetector array is mechanically and electrically connected to the ASIC (see Figure 2), either by use of indium bump bonds or by use of conductive epoxy bumps on the CdZnTe array joined to gold bumps on the ASIC. Hence, the output of each pixel detector is fed to its own amplifier chain.

  13. The development of X-ray flare onsets near active region filaments

    NASA Technical Reports Server (NTRS)

    Kahler, S. W.

    1981-01-01

    Skylab X-ray images of the early phases of six active region transient brightenings were compared with simultaneous H-alpha images to study the spatial relationships between filaments and the X-ray brightenings. When the X-ray loops were roughly perpendicular to the axes of the H-alpha filaments, the filaments did not disappear. X-ray loops which appeared nearly parallel to the filaments were generally associated with the disappearances of those filaments. It is suggested that the perpendicular loops correspond to the class I X-ray flares of Pallavicinic et al. (1977) while the parallel loops are the early phases of their class II flares characterized in the decay phases by arcades of large loops with low energy densities. Both kinds of X-ray flares can be associated with impulsive phases.

  14. Equal-Curvature X-ray Telescope Designs for Constellation-X Mission

    NASA Technical Reports Server (NTRS)

    Saha, Timo T.; Content, David A.; Zhang, William W.

    2003-01-01

    We study grazing incidence Equal-Curvature telescope designs for the Constellation-X mission. These telescopes have nearly spherical axial surfaces. The telescopes are designed so that the axial curvature is the same on the primary and secondary. The optical performance of these telescopes is for all practical purposes identical to the equivalent Wolter telescopes.

  15. Studies of the Origin of High-frequency Quasi-periodic Oscillations of Mass-accreting Black Holes in X-Ray Binaries with Next-generation X-Ray Telescopes

    NASA Astrophysics Data System (ADS)

    Beheshtipour, Banafsheh; Hoormann, Janie K.; Krawczynski, Henric

    2016-08-01

    Observations with RXTE (Rossi X-ray Timing Explorer) revealed the presence of high-frequency quasi-periodic oscillations (HFQPOs) of the X-ray flux from several accreting stellar-mass black holes. HFQPOs (and their counterparts at lower frequencies) may allow us to study general relativity in the regime of strong gravity. However, the observational evidence today does not yet allow us to distinguish between different HFQPO models. In this paper we use a general-relativistic ray-tracing code to investigate X-ray timing spectroscopy and polarization properties of HFQPOs in the orbiting Hotspot model. We study observational signatures for the particular case of the 166 Hz quasi-periodic oscillation (QPO) in the galactic binary GRS 1915+105. We conclude with a discussion of the observability of spectral signatures with a timing-spectroscopy experiment such as the LOFT (Large Observatory for X-ray Timing) and polarization signatures with space-borne X-ray polarimeters such as IXPE (Imaging X-ray Polarimetry Explorer), PolSTAR (Polarization Spectroscopic Telescope Array), PRAXyS(Polarimetry of Relativistic X-ray Sources), or XIPE (X-ray Imaging Polarimetry Explorer). A mission with high count rate such as LOFT would make it possible to get a QPO phase for each photon, enabling the study of the QPO-phase-resolved spectral shape and the correlation between this and the flux level. Owing to the short periods of the HFQPOs, first-generation X-ray polarimeters would not be able to assign a QPO phase to each photon. The study of QPO-phase-resolved polarization energy spectra would thus require simultaneous observations with a first-generation X-ray polarimeter and a LOFT-type mission.

  16. Experimental study and analytical model of deformation of magnetostrictive films as applied to mirrors for x-ray space telescopes.

    PubMed

    Wang, Xiaoli; Knapp, Peter; Vaynman, S; Graham, M E; Cao, Jian; Ulmer, M P

    2014-09-20

    The desire for continuously gaining new knowledge in astronomy has pushed the frontier of engineering methods to deliver lighter, thinner, higher quality mirrors at an affordable cost for use in an x-ray observatory. To address these needs, we have been investigating the application of magnetic smart materials (MSMs) deposited as a thin film on mirror substrates. MSMs have some interesting properties that make the application of MSMs to mirror substrates a promising solution for making the next generation of x-ray telescopes. Due to the ability to hold a shape with an impressed permanent magnetic field, MSMs have the potential to be the method used to make light weight, affordable x-ray telescope mirrors. This paper presents the experimental setup for measuring the deformation of the magnetostrictive bimorph specimens under an applied magnetic field, and the analytical and numerical analysis of the deformation. As a first step in the development of tools to predict deflections, we deposited Terfenol-D on the glass substrates. We then made measurements that were compared with the results from the analytical and numerical analysis. The surface profiles of thin-film specimens were measured under an external magnetic field with white light interferometry (WLI). The analytical model provides good predictions of film deformation behavior under various magnetic field strengths. This work establishes a solid foundation for further research to analyze the full three-dimensional deformation behavior of magnetostrictive thin films.

  17. ART-XC: A Medium-energy X-ray Telescope System for the Spectrum-R-Gamma Mission

    NASA Technical Reports Server (NTRS)

    Arefiev, V.; Pavlinsky, M.; Lapshov, I.; Thachenko, A.; Sazonov, S.; Revnivtsev, M.; Semena, N.; Buntov,M.; Vikhlinin, A.; Gubarev, M.; ODell, S.; Ramsey, B.; Romaine, S.; Swartz. D/; Weisskopf, M.; Hasinger, G.; Predehl, P.; Grigorovich, S.; Litvin, D.; Meidinger, N.; Strueder, L. W.

    2008-01-01

    The ART-XC instrument is an X-ray grazing-incidence telescope system in an ABRIXAS-type optical configuration optimized for the survey observational mode of the Spectrum-RG astrophysical mission which is scheduled to be launched in 2011. ART-XC has two units, each equipped with four identical X-ray multi-shell mirror modules. The optical axes of the individual mirror modules are not parallel but are separated by several degrees to permit the four modules to share a single CCD focal plane detector, 1/4 of the area each. The 450-micron-thick pnCCD (similar to the adjacent eROSITA telescope detector) will allow detection of X-ray photons up to 15 keV. The field of view of the individual mirror module is about 18 x 18 arcminutes(exp 2) and the sensitivity of the ART-XC system for 4 years of survey will be better than 10(exp -12) erg s(exp -1) cm(exp -2) over the 4-12 keV energy band. This will allow the ART-XC instrument to discover several thousand new AGNs.

  18. ART-XC: a medium-energy x-ray telescope system for the Spectrum-R-Gamma mission

    NASA Astrophysics Data System (ADS)

    Arefiev, V.; Pavlinsky, M.; Lapshov, I.; Tkachenko, A.; Sazonov, S.; Revnivtsev, M.; Semena, N.; Buntov, M.; Vikhlinin, A.; Gubarev, M.; O'Dell, S.; Ramsey, B.; Romaine, S.; Swartz, D.; Weisskopf, M.; Hasinger, G.; Predehl, P.; Grigorovich, S.; Litvin, D.; Meidinger, N.; Strüder, L. W.

    2008-07-01

    The ART-XC instrument is an X-ray grazing-incidence telescope system in an ABRIXAS-type optical configuration optimized for the survey observational mode of the Spectrum-RG astrophysical mission which is scheduled to be launched in 2011. ART-XC has two units, each equipped with four identical X-ray multi-shell mirror modules. The optical axes of the individual mirror modules are not parallel but are separated by several degrees to permit the four modules to share a single CCD focal plane detector, 1/4 of the area each. The 450-micron-thick pnCCD (similar to the adjacent eROSITA telescope detector) will allow the detection of X-ray photons up to 15 keV. The field of view of the individual mirror module is about 18×18 arcminutes2 and the sensitivity of the ART-XC system for 4 years of survey will be better than 10-12 erg s-1 cm-2 over the 4-12 keV energy band. This will allow the ART-XC instrument to discover several thousands new AGNs.

  19. X-Ray Activity in the Open Cluster IC 4665

    NASA Technical Reports Server (NTRS)

    Giamapapa, Mark S.; Prosser, Charles F.; Fleming, Thomas A.

    1997-01-01

    We present the results of a joint ROSAT High Resolution Imager (HRI) and optical investigation of the open cluster IC 4665. The ROSAT data contains detections for 28 stellar sources in the field, including 22 cluster members and candidate members spanning the color range -0.18 less than or equal to (B - V(sub o)) less than or equal to +1.63 (approx. B3 - M3). Upper limits are given for the remaining members (or candidate members) in the HRI field. Keck HIRES spectra have been obtained that yield radial and rotational velocity measures, respectively, for faint, low mass candidate members located within the field of the ROSAT HRI observation. In addition, photometry of possible optical counterparts to previously uncatalogued X-ray sources in the HRI field is presented. The trends in X-ray properties with (B - V) color in IC 4665 are found to be quite similar to that for other, more nearby young clusters such as the Pleiades and alpha Persei. In particular, a maximum in normalized X-ray luminosity of log (L(sub x)/L(sub bol)) approx. equal 3 is observed, beginning in the color range of (B - V)(sub o) = 0.7 - 0.8. This is similar to the corresponding color range among Pleiades members, in agreement with the earlier estimate, that the age of IC 4665 is similar to the age of the Pleiades. The correlation of rotation and X-ray emission levels is consistent with that in other young clusters. Among the high mass stars in IC 4665, five B stars are detected as X-ray sources. Of these, one is a spectroscopic binary while the remaining objects are apparently single staxs. The level of intrinsic X-ray emission observed in the rapidly rotating (v sini greater than 200 km/ s), single B stars is consistent with an origin due to shock heating of the ambient medium by radiatively driven, rotationally enhanced winds. On the basis of these observations and the results for other clusters, we argue that observed levels of X-ray emission in high mass stars of log (L(sub x)/L(sub bol

  20. Outflowing X-ray corona in Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Wang, Junxian; Liu, Teng; Yang, Huan; Zhu, Feifan; Zhou, Youyuan

    2015-08-01

    Hard X-ray emission in radio-quiet AGNs is believed to be produced via inverse Compton scattering by hot and compact corona near the super massive black hole. However the origin and physical properties of the coronae, including geometry, kinematics and dynamics, yet remain poorly known. Taking [OIV] 25.89um emission line as an isotropic indicator of AGN's intrinsic luminosity, we compare the intrinsic corona X-ray emission between Seyfert 1 and Compton-thin Seyfert 2 galaxies, which are viewed at different inclinations according to the unification scheme. We find that Seyfert 1 galaxies are brighter in "absorption-corrected" 2-10 keV emission by a factor of ~2.8, comparing with Compton-thin Seyfert 2 galaxies. The Seyfert 1 and Compton-thin Seyfert 2 galaxies follow a statistically identical correlation between the absorption-corrected 2-10 keV luminosity and the SWIFT BAT 14-195 keV luminosity, indicating that our absorption correction to the 2-10 keV flux is sufficient. The difference between the two populations thus can not be attributed to X-ray absorption, and instead implies an intrinsic anisotropy in the corona X-ray emission. This striking anisotropy of X-ray emission can be explained by a bipolar outflowing corona with a bulk velocity of ~0.3-0.5c. This would provide a natural link between the so-called coronae and weak jets in these systems. We also show that how this study would affect our understanding to the nature of mid-infrared emission in AGNs and the properties of dusty torus. Furthermore, such anisotropy implies that, contrary to previous understanding based on the assumption of isotropic corona emission, hard X-ray AGN surveys are biased against type 2 AGNs even after absorption-correction, and careful correction for this effect is required to measure the obscured fraction from X-ray surveys. Other interesting consequences of this discovery will also be discussed.

  1. High resolution imaging with multilayer soft x-ray, EUV and FUV telescopes of modest aperture and cost

    SciTech Connect

    Walker, A.B.C. Jr.; Lindblom, J.F.; Timothy, J.G. . Center for Space Science and Astrophysics); Hoover, R.B. . George C. Marshall Space Flight Center); Barbee, T.W. Jr. ); Baker, P.C. ); Powell, F.R. (Luxel, Inc., Friday Har

    1990-04-01

    The development of multilayer reflective coatings now permits soft x- ray, EUV and FUV radiation ({lambda}{lambda} {approximately} 40{angstrom}--2000{angstrom}) to be efficiently imaged by conventional normal incidence optical configurations. Telescopes with quite modest apertures ({approximately}0.1--0.5 meters) can, in principle, achieve images with resolutions ({approximately}0.1 arc- second or better) which would require apertures of 1.25 meters or more at visible wavelengths. We review the progress which has been made in developing compact telescopes for ultra-high resolution imaging of the sun at soft x-ray, EUV and FUV wavelengths, including laboratory test results and astronomical images obtained with rocket- borne multilayer telescopes. We discuss the factors which limit the resolution which has been achieved so far, and the problems which must be addressed to attain, and surpass the 0.1 arc-second level. We also describe the application of these technologies to the development of solar telescopes for future space missions. 64 refs., 5 figs., 1 tab.

  2. Calibration of the High Energy Replicated Optics to Explore the Sun (HEROES) Hard X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.; Gaskin, Jessica; Christe, Steven; Shih, Albert; Tennant, Allyn; Swartz, Doug; Kilaru, Kiranmayee; Elsner, Ron; Kolodziejczak, Jeff; Ramsey, Brian

    2014-01-01

    On September 21-22, 2013, the High Energy Replicated Optics to Explore the Sun (HEROES) hard X-ray telescope, flew as a balloon payload from Ft. Sumner, N.M. HEROES observed the Sun, the black hole binary GRS 1915+105, and the Crab Nebula during its 27 hour flight. In this paper we describe laboratory calibration measurements of the HEROES detectors using line and continuum sources, applications of these measurements to define channel to energy (gain) corrections for observed events and to define detector response matrices. We characterize the HEROES X-ray grazing incidence optics using measurements taken in the Stray-Light (SLF) Facility in Huntsville, AL, and using ray traces.

  3. Mathematical Design Optimization of Wide-Field X-ray Telescopes: Mirror Nodal Positions and Detector Tilts

    NASA Technical Reports Server (NTRS)

    Elsner, R. F.; O'Dell, S. L.; Ramsey, B. D.; Weisskopf, M. C.

    2011-01-01

    We describe a mathematical formalism for determining the mirror shell nodal positions and detector tilts that optimize the spatial resolution averaged over a field-of-view for a nested x-ray telescope, assuming known mirror segment surface prescriptions and known detector focal surface. The results are expressed in terms of ensemble averages over variable combinations of the ray positions and wave vectors in the flat focal plane intersecting the optical axis at the nominal on-axis focus, which can be determined by Monte-Carlo ray traces of the individual mirror shells. This work is part of our continuing efforts to provide analytical tools to aid in the design process for wide-field survey x-ray astronomy missions.

  4. Calibration of the High Energy Replicated Optics to Explore the Sun (HEROES) Hard X-ray Telescope

    NASA Astrophysics Data System (ADS)

    Wilson-Hodge, Colleen A.; Gaskin, Jessica; Christe, Steven; Shih, Albert; Tennant, Allyn; Swartz, Doug; Kilaru, Kiranmayee; Elsner, Ron; Kolodziejczak, Jeff; Ramsey, Brian

    On 2013 September 21-22, the High Energy Replicated Optics to Explore the Sun (HEROES) hard X-ray telescope flew as a balloon payload from Ft. Sumner, NM. HEROES observed the Sun, the black hole binary GRS 1915+105, and the Crab Nebula during its 27 h flight. In this paper, we describe laboratory calibration measurements of the HEROES detectors using line and continuum sources and applications of these measurements to define channel to energy (gain) corrections for observed events and to define detector response matrices. We characterize the HEROES X-ray grazing incidence optics using measurements taken in the Stray Light Facility (SLF) in Huntsville, AL, and using ray traces. We describe the application of our calibration measurements to in-flight observations of the Crab Nebula.

  5. Mathematical Design Optimization of Wide-Field X-ray Telescopes: Mirror Nodal Positions and Detector Tilts

    NASA Technical Reports Server (NTRS)

    Elsner, Ronald; O'Dell, Stephen; Ramsey, Brian; Weisskopf, Martin

    2011-01-01

    We describe a mathematical formalism for determining the mirror shell nodal positions and detector tilts that optimize the spatial resolution averaged over a field-of-view for a nested x-ray telescope, assuming known mirror segment surface prescriptions and known detector focal surface. The results are expressed in terms of ensemble averages over variable combinations of the ray positions and wavevectors in the flat focal plane intersecting the optical axis at the nominal on-axis focus, which can be determined by Monte-Carlo ray traces of the individual mirror shells. This work is part of our continuing efforts to provide analytical tools to aid in the design process for wide-field survey x-ray astronomy missions.

  6. Imaging Analysis of the Hard X-Ray Telescope ProtoEXIST2 and New Techniques for High-resolution Coded-aperture Telescopes

    NASA Astrophysics Data System (ADS)

    Hong, Jaesub; Allen, Branden; Grindlay, Jonathan; Barthelmy, Scott

    2017-01-01

    Wide-field (≳100 deg{}2) hard X-ray coded-aperture telescopes with high angular resolution (≲2‧) will enable a wide range of time domain astrophysics. For instance, transient sources such as gamma-ray bursts can be precisely localized without the assistance of secondary focusing X-ray telescopes to enable rapid followup studies. On the other hand, high angular resolution in coded-aperture imaging introduces a new challenge in handling the systematic uncertainty: the average photon count per pixel is often too small to establish a proper background pattern or model the systematic uncertainty in a timescale where the model remains invariant. We introduce two new techniques to improve detection sensitivity, which are designed for, but not limited to, a high-resolution coded-aperture system: a self-background modeling scheme which utilizes continuous scan or dithering operations, and a Poisson-statistics based probabilistic approach to evaluate the significance of source detection without subtraction in handling the background. We illustrate these new imaging analysis techniques in high resolution coded-aperture telescope using the data acquired by the wide-field hard X-ray telescope ProtoEXIST2 during a high-altitude balloon flight in fall 2012. We review the imaging sensitivity of ProtoEXIST2 during the flight, and demonstrate the performance of the new techniques using our balloon flight data in comparison with a simulated ideal Poisson background.

  7. High-Sensitivity X-ray Polarimetry with Amorphous Silicon Active-Matrix Pixel Proportional Counters

    NASA Technical Reports Server (NTRS)

    Black, J. K.; Deines-Jones, P.; Jahoda, K.; Ready, S. E.; Street, R. A.

    2003-01-01

    Photoelectric X-ray polarimeters based on pixel micropattern gas detectors (MPGDs) offer order-of-magnitude improvement in sensitivity over more traditional techniques based on X-ray scattering. This new technique places some of the most interesting astronomical observations within reach of even a small, dedicated mission. The most sensitive instrument would be a photoelectric polarimeter at the focus of 2 a very large mirror, such as the planned XEUS. Our efforts are focused on a smaller pathfinder mission, which would achieve its greatest sensitivity with large-area, low-background, collimated polarimeters. We have recently demonstrated a MPGD polarimeter using amorphous silicon thin-film transistor (TFT) readout suitable for the focal plane of an X-ray telescope. All the technologies used in the demonstration polarimeter are scalable to the areas required for a high-sensitivity collimated polarimeter. Leywords: X-ray polarimetry, particle tracking, proportional counter, GEM, pixel readout

  8. A Normal Incidence X-ray Telescope (NIXT) Sounding Rocket Payload

    NASA Technical Reports Server (NTRS)

    Golub, Leon

    1997-01-01

    The following two papers, summarizing scientific results from the NIXT rocket program, are presented: (1) 'The Solar X-ray Corona,' - an introduction to the physics of the solar corona, with a major portion concerning a summary of results from the series of NIXT sounding rocket flights; and (2) 'Difficulties in Observing Coronal Structure.'

  9. THE FIRST HARD X-RAY POWER SPECTRAL DENSITY FUNCTIONS OF ACTIVE GALACTIC NUCLEUS

    SciTech Connect

    Shimizu, T. Taro; Mushotzky, Richard F.

    2013-06-10

    We present results of our power spectral density (PSD) analysis of 30 active galactic nuclei (AGNs) using the 58 month light curves from Swift's Burst Alert Telescope (BAT) in the 14-150 keV band. PSDs were fit using a Monte Carlo based algorithm to take into account windowing effects and measurement error. All but one source were found to be fit very well using an unbroken power law with a slope of {approx} - 1, consistent at low frequencies with previous studies in the 2-10 keV band, with no evidence of a break in the PSD. For five of the highest signal-to-noise ratio sources, we tested the energy dependence of the PSD and found no significant difference in the PSD at different energies. Unlike previous studies of X-ray variability in AGNs, we do not find any significant correlations between the hard X-ray variability and different properties of the AGN including luminosity and black hole mass. The lack of break frequencies and correlations seem to indicate that AGNs are similar to the high state of Galactic black holes.

  10. Using the EXIST Active Shields for Earth Occultation Observations of X-Ray Sources

    NASA Technical Reports Server (NTRS)

    Wilson, Colleen A.; Fishman, Gerald; Hong, Jae-Sub; Gridlay, Jonathan; Krawczynski, Henric

    2005-01-01

    The EXIST active shields, now being planned for the main detectors of the coded aperture telescope, will have approximately 15 times the area of the BATSE detectors; and they will have a good geometry on the spacecraft for viewing both the leading and training Earth's limb for occultation observations. These occultation observations will complement the imaging observations of EXIST and can extend them to higher energies. Earth occultatio observations of the hard X-ray sky with BATSE on the Compton Gamma Ray Observatory developed and demonstrated the capabilities of large, flat, uncollimated detectors for this method. With BATSE, a catalog of 179 X-ray sources was monitored twice every spacecraft orbit for 9 years at energies above about 25 keV, resulting in 83 definite detections and 36 possible detections with 5-sigma detection sensitivities of 3.5-20 mcrab (20-430 keV) depending on the sky location. This catalog included four transients discovered with this technique and many variable objects (galactic and extragalactic). This poster will describe the Earth occultation technique, summarize the BATSE occultation observations, and compare the basic observational parameters of the occultation detector elements of BATSE and EXIST.

  11. A COMPARISON OF X-RAY AND MID-INFRARED SELECTION OF OBSCURED ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Eckart, Megan E.; Harrison, Fiona A.; McGreer, Ian D.; Helfand, David J.; Stern, Daniel

    2010-01-01

    We compare the relative merits of active galactic nuclei (AGNs) selection at X-ray and mid-infrared wavelengths using data from moderately deep fields observed by both Chandra and Spitzer. The X-ray-selected AGN sample and associated photometric and spectroscopic optical follow-up are drawn from a subset of fields studied as part of the Serendipitous Extragalactic X-ray Source Identification (SEXSI) program. Mid-infrared data in these fields are derived from targeted and archival Spitzer imaging, and mid-infrared AGN selection is accomplished primarily through application of the Infrared Array Camera (IRAC) color-color AGN 'wedge' selection technique. Nearly all X-ray sources in these fields which exhibit clear spectroscopic signatures of AGN activity have mid-infrared colors consistent with IRAC AGN selection. These are predominantly the most luminous X-ray sources. X-ray sources that lack high-ionization and/or broad lines in their optical spectra are far less likely to be selected as AGNs by mid-infrared color selection techniques. The fraction of X-ray sources identified as AGNs in the mid-infrared increases monotonically as the X-ray luminosity increases. Conversely, only 22% of mid-infrared-selected AGNs are detected at X-ray energies in the moderately deep ((t{sub exp}) approx 100 ks) SEXSI Chandra data. We hypothesize that IRAC sources with AGN colors that lack X-ray detections are predominantly high-luminosity AGNs that are obscured and/or lie at high redshift. A stacking analysis of X-ray-undetected sources shows that objects in the mid-infrared AGN selection wedge have average X-ray fluxes in the 2-8 keV band 3 times higher than sources that fall outside the wedge. Their X-ray spectra are also harder. The hardness ratio of the wedge-selected stack is consistent with moderate intrinsic obscuration, but is not suggestive of a highly obscured, Compton-thick source population. It is evident from this comparative study that in order to create a complete

  12. Comparing Data from Telescopic X-Ray Instruments: Can We Trust All Satellites?

    NASA Astrophysics Data System (ADS)

    Joyce, Quianah T.; Fortenberry, Alexander; Gendre, Bruce

    2017-01-01

    In astronomy and astrophysics, X-ray emissions from cosmic entities aid in revealing what type of sources they emanate from. Swift, NASA’s latest X-ray satellite, has not been operating at its intended configurations. The satellite is experiencing difficulties maintaining a stable temperature in its charge capture device. This research intends to determine if this complication causes discrepancies in Swift’s collected data by using gamma-ray burst data. Gamma-ray bursts are excellent comparison candidates due to their brightness and fluctuations. We compared archived data of GRB 130427A and GRB 090423A from Swift and the European Space Agency’s XMM-Newton observatory. Next, we reduced the data and produced the respective spectra. We then analyzed and compared the spectra to one another to find any discrepancies. We have determined, based on data analysis of the spectra, that Swift is working properly despite the cooling malfunction.

  13. Imaging performance of a normal incidence soft X-ray telescope

    NASA Astrophysics Data System (ADS)

    Henry, J. P.; Spiller, E.; Weisskopf, M.

    1982-01-01

    Measurements are presented of the imaging performance of a normal incidence spherical soft X-ray mirror at BK-alpha (67.6 A). The reflector was a 124-layer coating consisting of alternating Re-W alloy and C layers with a protective C overcoat 34 A thick deposited on a Zerodur substrate. Measurements made at an angle of 1.5 deg off axis with the prototype of the Einstein Observatory high resolution imager reveal the resolution of the mirror to be about 1 arcsec FWHM, with 50% of the reflected power within the detector field of 512 arcsec contained within a diameter of 5 arcsec. The data demonstrate the practicality and potential good performance of normal-incidence soft X-ray optics, and show that the scattering performances of such devices may be as good or better than the best grazing incidence devices.

  14. Electroform replication of grazing incidence X-ray optics. [spaceborne telescopes

    NASA Technical Reports Server (NTRS)

    Ulmer, M. P.; Purcell, W. R.; Bedford, D.; Simnett, G. R.

    1985-01-01

    Work to produce mirrors via electroform replication is reported. Work on small (6 cm by 9 cm) cylindrical pieces and on 40 cm long by 12 cm wide Wolter shaped mirrors is summarized. It is shown that electroforming is a viable technique for producing relatively inexpensive grazing incidence X-ray optics, as long as modest resolution (1 min of arc) and size (12 cm diameter by 40 cm long) are specified.

  15. Super-smooth processing x-ray telescope application research based on the magnetorheological finishing (MRF) technology

    NASA Astrophysics Data System (ADS)

    Zhong, Xianyun; Hou, Xi; Yang, Jinshan

    2016-09-01

    Nickel is the unique material in the X-ray telescopes. And it has the typical soft material characteristics with low hardness high surface damage and low stability of thermal. The traditional fabrication techniques are exposed to lots of problems, including great surface scratches, high sub-surface damage and poor surface roughness and so on. The current fabrication technology for the nickel aspheric mainly adopt the single point diamond turning(SPDT), which has lots of advantages such as high efficiency, ultra-precision surface figure, low sub-surface damage and so on. But the residual surface texture of SPDT will cause great scattering losses and fall far short from the requirement in the X-ray applications. This paper mainly investigates the magnetorheological finishing (MRF) techniques for the super-smooth processing on the nickel optics. Through the study of the MRF polishing techniques, we obtained the ideal super-smooth polishing technique based on the self-controlled MRF-fluid NS-1, and finished the high-precision surface figure lower than RMS λ/80 (λ=632.8nm) and super-smooth roughness lower than Ra 0.3nm on the plane reflector and roughness lower than Ra 0.4nm on the convex cone. The studying of the MRF techniques makes a great effort to the state-of-the-art nickel material processing level for the X-ray optical systems applications.

  16. HERO: A Balloon-Borne Hard-X-Ray Focusing Telescope

    NASA Astrophysics Data System (ADS)

    Ramsey, Brian

    HERO, for High Energy Replicated Optics, is an evolutionary balloon payload featuring hard-xray grazing-incidence nickel optics. The HERO payload is designed to perform high-sensitivity, fine spatial resolution observations of galactic and extragalactic sources in an energy range that is as yer unexplored with grazing-incidence optics. A proof-of-concept flight with just 6 x-ray mirrors was completed in 2001 and captured the first focused hard-x-ray images galactic sources. Since that time, the payload has been greatly expanded and now features 100, in-house-fabricated mirror shells with an attendant large increase in sensitivity. In its current form, HERO was flown in 2007, from Fort Sumner, NM, and is schedules to fly again in September 2009, from Alice Springs, NT. Full details of the HERO payload will be provided in this presentation together with a discussion of the challenges of flying moderate resolution x-ray optics from a balloon platform.

  17. THE SWIFT X-RAY TELESCOPE CLUSTER SURVEY. III. CLUSTER CATALOG FROM 2005-2012 ARCHIVAL DATA

    SciTech Connect

    Liu, Teng; Wang, Jun-Xian; Tozzi, Paolo; Tundo, Elena; Moretti, Alberto; Rosati, Piero; Tagliaferri, Gianpiero; Campana, Sergio; Giavalisco, Mauro

    2015-02-01

    We present the Swift X-ray Cluster Survey (SWXCS) catalog obtained using archival data from the X-ray telescope (XRT) on board the Swift satellite acquired from 2005 February to 2012 November, extending the first release of the SWXCS. The catalog provides positions, soft fluxes, and, when possible, optical counterparts for a flux-limited sample of X-ray group and cluster candidates. We consider the fields with Galactic latitude |b| > 20° to avoid high H I column densities. We discard all of the observations targeted at groups or clusters of galaxies, as well as particular extragalactic fields not suitable to search for faint extended sources. We finally select ∼3000 useful fields covering a total solid angle of ∼400 deg{sup 2}. We identify extended source candidates in the soft-band (0.5-2 keV) images of these fields using the software EXSdetect, which is specifically calibrated for the XRT data. Extensive simulations are used to evaluate contamination and completeness as a function of the source signal, allowing us to minimize the number of spurious detections and to robustly assess the selection function. Our catalog includes 263 candidate galaxy clusters and groups down to a flux limit of 7 × 10{sup –15} erg cm{sup –2} s{sup –1} in the soft band, and the logN-logS is in very good agreement with previous deep X-ray surveys. The final list of sources is cross-correlated with published optical, X-ray, and Sunyaev-Zeldovich catalogs of clusters. We find that 137 sources have been previously identified as clusters in the literature in independent surveys, while 126 are new detections. Currently, we have collected redshift information for 158 sources (60% of the entire sample). Once the optical follow-up and the X-ray spectral analysis of the sources are complete, the SWXCS will provide a large and well-defined catalog of groups and clusters of galaxies to perform statistical studies of cluster properties and tests of cosmological models.

  18. The Swift X-Ray Telescope Cluster Survey. III. Cluster Catalog from 2005-2012 Archival Data

    NASA Astrophysics Data System (ADS)

    Liu, Teng; Tozzi, Paolo; Tundo, Elena; Moretti, Alberto; Rosati, Piero; Wang, Jun-Xian; Tagliaferri, Gianpiero; Campana, Sergio; Giavalisco, Mauro

    2015-02-01

    We present the Swift X-ray Cluster Survey (SWXCS) catalog obtained using archival data from the X-ray telescope (XRT) on board the Swift satellite acquired from 2005 February to 2012 November, extending the first release of the SWXCS. The catalog provides positions, soft fluxes, and, when possible, optical counterparts for a flux-limited sample of X-ray group and cluster candidates. We consider the fields with Galactic latitude |b| > 20° to avoid high H I column densities. We discard all of the observations targeted at groups or clusters of galaxies, as well as particular extragalactic fields not suitable to search for faint extended sources. We finally select ~3000 useful fields covering a total solid angle of ~400 deg2. We identify extended source candidates in the soft-band (0.5-2 keV) images of these fields using the software EXSdetect, which is specifically calibrated for the XRT data. Extensive simulations are used to evaluate contamination and completeness as a function of the source signal, allowing us to minimize the number of spurious detections and to robustly assess the selection function. Our catalog includes 263 candidate galaxy clusters and groups down to a flux limit of 7 × 10-15 erg cm-2 s-1 in the soft band, and the logN-logS is in very good agreement with previous deep X-ray surveys. The final list of sources is cross-correlated with published optical, X-ray, and Sunyaev-Zeldovich catalogs of clusters. We find that 137 sources have been previously identified as clusters in the literature in independent surveys, while 126 are new detections. Currently, we have collected redshift information for 158 sources (60% of the entire sample). Once the optical follow-up and the X-ray spectral analysis of the sources are complete, the SWXCS will provide a large and well-defined catalog of groups and clusters of galaxies to perform statistical studies of cluster properties and tests of cosmological models.

  19. The Active Nucleus and 200-KPC X-Ray Jet in NGC 6251

    NASA Astrophysics Data System (ADS)

    Hardcastle, Martin

    2002-09-01

    The jet of the FRI radio galaxy NGC 6251 is known to be an X-ray source on scales out to 200 kpc from the nucleus, making it the largest-scale FRI X-ray jet known. However, existing observations do not provide adequate information on the structure or spectrum of any of the X-ray jet components or on the spectrum of the active nucleus. We propose to make a sensitive observation of this unique object. We will measure the X-ray spectrum at multiple points along the jet to determine the emission mechanism and search for differences in particle acceleration as a function of distance. We will also determine whether the hot gas around the jet has pressure sufficient to confine it, and we will make a good spectrum of the X-ray nucleus for comparison with radio and optical observations.

  20. The Milli-Arc-Second Structure Imager, MASSIM: A New Concept for a High Angular Resolution X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Skinner, Gerry; Arzoumanian, Z.; Cash, W.; Gehrels, N.; Gendreau, K.; Gorenstein, P.; Krizmanic, J.; Leitner, J.; Miller, M.; Reasenberg, R.; Reynolds, C.; Sambruna, R.; Streitmatter, R.; Windt, D.

    2008-01-01

    MASSIM, the Milli-Arc-Second Structure Imager, is a mission that has been proposed for study within the context of NASA's "Astrophysics Strategic Mission Concept Studies" program. It uses a set of achromatic diffractive-refractive Fresnel lenses on an optics spacecraft to focus 5-11 keV X-rays onto detectors on a second spacecraft flying in formation 1000 km away. It will have a point-source sensitivity comparable with that of the current generation of major X-ray observatories (Chandra, XMM-Newton) but an angular resolution some three orders of magnitude better. MASSIM is optimized for the study of jets and other phenomena that occur in the immediate vicinity of black holes and neutron stars. It can also be used for studying other astrophysical phenomena on the milli-arc-second scale, such as those involving proto-stars, the surfaces and surroundings of nearby active stars and interacting winds. After introducing the principle of diffractive imaging in the x-ray/gamma-ray regime, the MASSIM mission concept and baseline design will be described along with a discussion of the options and trade-offs within the X-ray optics design.

  1. Soft X-ray Images of the Solar Corona with a Normal-Incidence Cassegrain Multilayer Telescope.

    PubMed

    Walker, A B; Lindblom, J F; Barbee, T W; Hoover, R B

    1988-09-30

    High-resolution images of the sun in the soft x-ray to extreme ultraviolet(EUV) regime have been obtained with normal-incidence Cassegrain multilayer telescopes operated from a sounding rocket in space. The inherent energy-selective property of multilayer-coated optics allowed distinct groups of emission lines to be isolated in the solar corona and the transition region. The Cassegrain telescopes provided images in bands centered at 173 and 256 angstroms. The bandpass centered at 173 angstroms is dominated by emission from the ions Fe IX Fe X. This emission is from coronal plasma in the temperature range 0.8 x 10(6) to 1.4 x 10(6)K. The images have angular resolution of about 1.0 to 1.5 arc seconds, and show no degradation because of x-ray scattering. Many features of coronal structure, including magnetically confined loops of hot plasma, coronal plumes, polar coronal holes, faint structures on the size scale of supergranulation and smaller, and features due to overlying cool prominences are visible in the images. The density structure of polar plumes, which are thought to contribute to the solar wind, has been derived from the observations out to 1.7 solar radii.

  2. Analysis of X-ray and EUV spectra of solar active regions

    NASA Technical Reports Server (NTRS)

    Strong, K. T.; Acton, L. W.

    1979-01-01

    Data acquired by two flights of an array of six Bragg crystal spectrometers on an Aerobee rocket to obtain high spatial and spectral resolution observations of various coronal features at soft X-ray wavelengths (9-23A) were analyzed. The various aspects of the analysis of the X-ray data are described. These observations were coordinated with observations from the experiments on the Apollo Telescope Mount and the various data sets were related to one another. The Appendices contain the published results, abstracts of papers, computer code descriptions and preprints of papers, all produced as a result of this research project.

  3. A Normal Incidence X-ray Telescope (NIXT) Sounding Rocket Payload

    NASA Technical Reports Server (NTRS)

    Golub, Leon

    1998-01-01

    The solar corona, and the coronae of solar-type stars, consist of a low-density magnetized plasma at temperatures exceeding 10(exp 6) K. The primary coronal emission is therefore in the UV and soft X-ray range. The observed close connection between solar magnetic fields and the physical parameters of the corona implies a fundamental role for the magnetic field in coronal structuring and dynamics. Variability of the corona occurs on all temporal and spatial scales - at one extreme, as the result of plasma instabilities, and at the other extreme driven by the global magnetic flux emergence patterns of the solar cycle.

  4. Early evolution of an X-ray emitting solar active region

    NASA Technical Reports Server (NTRS)

    Wolfson, C. J.; Acton, L. W.; Leibacher, J. W.; Roethig, D. T.

    1977-01-01

    The birth and early evolution of a solar active region has been investigated using X-ray observations from the mapping X-ray heliometer on board the OSO-8 spacecraft. X-ray emission is observed within three hours of the first detection of H-alpha plage. At that time, a plasma temperature of four million K in a region having a density on the order of 10 to the 10th power per cu cm is inferred. During the fifty hours following birth almost continuous flares or flare-like X-ray bursts are superimposed on a monotonically increasing base level of X-ray emission produced by the plasma. If the X-rays are assumed to result from heating due to dissipation of current systems or magnetic field reconnection, it may be concluded that flare-like X-ray emission soon after active region birth implies that the magnetic field probably emerges in a stressed or complex configuration.

  5. Miniaturized X-ray telescope for VZLUSAT-1 nanosatellite with Timepix detector

    NASA Astrophysics Data System (ADS)

    Baca, T.; Platkevic, M.; Jakubek, J.; Inneman, A.; Stehlikova, V.; Urban, M.; Nentvich, O.; Blazek, M.; McEntaffer, R.; Daniel, V.

    2016-10-01

    We present the application of a Timepix detector on the VZLUSAT-1 nanosatellite. Timepix is a compact pixel detector (256×256 square pixels, 55×55 μm each) sensitive to hard X-ray radiation. It is suitable for detecting extraterrestrial X-rays due to its low noise characteristics, which enables measuring without special cooling. This project aims to verify the practicality of the detector in conjunction with 1-D Lobster-Eye optics to observe celestial sources between 5 and 20 keV. A modified USB interface (developed by IEAP at CTU in Prague) is used for low-level control of the Timepix. An additional 8-bit Atmel microcontroller is dedicated for commanding the detector and to process the data onboard the satellite. We present software methods for onboard post-processing of captured images, which are suitable for implementation under the constraints of the low-powered embedded hardware. Several measuring modes are prepared for different scenarios including single picture exposure, solar UV-light triggered exposure, and long-term all-sky monitoring. The work has been done within Medipix2 collaboration. The satellite is planned for launch in April 2017 as a part of the QB50 project with an end of life expectancy in 2019.

  6. Very high resolution UV and X-ray spectroscopy and imagery of solar active regions

    NASA Technical Reports Server (NTRS)

    Bruner, M.; Brown, W. A.; Haisch, B. M.

    1987-01-01

    A scientific investigation of the physics of the solar atmosphere, which uses the techniques of high resolution soft X-ray spectroscopy and high resolution UV imagery, is described. The experiments were conducted during a series of three sounding rocket flights. All three flights yielded excellent images in the UV range, showing unprecedented spatial resolution. The second flight recorded the X-ray spectrum of a solar flare, and the third that of an active region. A normal incidence multi-layer mirror was used during the third flight to make the first astronomical X-ray observations using this new technique.

  7. X-ray refelection from photoionized media in active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Zycki, Piotr T.; Krolik, Julian H.; Zdziarski, Andrzej A.; Kallman, Timothy R.

    1994-01-01

    We calculate the spectrum of X-ray radiation and reprocessed by a partly ionized optically thick medium in an active galactic nucleus. We self-consistently calculate the ionization balance and thermal balance in the medium along with the distribution of X-ray intensity with optical depth. In addition to absorption or scattering of the incident X-rays, we also compute the spectrum of X-rays emitted by the material, including lines, edges, and bremsstrahlung. The albedo of the medium depends primarily on the X-ray ionization parameter (ratio of incident flux to gas density, zeta(sub Chi), and secondarily on the UV flux generated by dissipation inside the disk; we locate the critical range of zeta(sub Chi) over which the albedo increases from small to nearly unity. While the continuum reflection is very weak below 10 keV when zeta(sub Chi) is small, significnat fluxes are emitted in atomic lines and edges in this energy range. In the limit of large zeta(sub Chi), the albedo below 10 keV increases, but reflection in this band is never gray: some photoelectric absorption remains up to rather large values of zeta(sub Chi), while at still higher values, inverse Compton scattering amplifies the soft X-ray flux. These features are sufficiently sharp that current and near-future X-ray experiments should permit diagnostic measures of zeta(sub Chi).

  8. X-ray and infrared diagnostics of nearby active galactic nuclei with MAXI and AKARI

    NASA Astrophysics Data System (ADS)

    Isobe, Naoki; Kawamuro, Taiki; Oyabu, Shinki; Nakagawa, Takao; Baba, Shunsuke; Yano, Kenichi; Ueda, Yoshihiro; Toba, Yoshiki

    2016-12-01

    Nearby active galactic nuclei were diagnosed in the X-ray and mid-to-far infrared wavelengths with Monitor of All-sky X-ray Image (MAXI) and the Japanese infrared observatory AKARI, respectively. One hundred of the X-ray sources listed in the second release of the MAXI all-sky X-ray source catalog are currently identified as non-blazar-type active galactic nuclei. These include 95 Seyfert galaxies and 5 quasars, and they are composed of 73 type-1 and 27 type-2 objects. The AKARI all-sky survey point source catalog was searched for their mid- and far-infrared counterparts at 9, 18, and 90 μm. As a result, 69 Seyfert galaxies in the MAXI catalog (48 type-1 and 21 type-2) were found to be detected with AKARI. The X-ray (3-4 keV and 4-10 keV) and infrared luminosities of these objects were investigated, together with their color information. Adopting the canonical photon index, Γ = 1.9, of the intrinsic X-ray spectrum of the Seyfert galaxies, the X-ray hardness ratio between the 3-4 and 4-10 keV ranges derived with MAXI was roughly converted into the absorption column density. After the X-ray luminosity was corrected for absorption from the estimated column density, the well-known X-ray-to-infrared luminosity correlation was confirmed, at least in the Compton-thin regime. In contrast, NGC 1365, the only Compton-thick object in the MAXI catalog, was found to deviate from the correlation toward a significantly lower X-ray luminosity by nearly an order of magnitude. It was verified that the relation between the X-ray hardness below 10 keV and X-ray-to-infrared color acts as an effective tool to pick up Compton-thick objects. The difference in the infrared colors between the type-1 and type-2 Seyfert galaxies and its physical implication on the classification and unification of active galactic nuclei are briefly discussed.

  9. X-ray spectrometer spectrograph telescope system. [for solar corona study

    NASA Technical Reports Server (NTRS)

    Bruner, E. C., Jr.; Acton, L. W.; Brown, W. A.; Salat, S. W.; Franks, A.; Schmidtke, G.; Schweizer, W.; Speer, R. J.

    1979-01-01

    A new sounding rocket payload that has been developed for X-ray spectroscopic studies of the solar corona is described. The instrument incorporates a grazing incidence Rowland mounted grating spectrograph and an extreme off-axis paraboloic sector feed system to isolate regions of the sun of order 1 x 10 arc seconds in size. The focal surface of the spectrograph is shared by photographic and photoelectric detection systems, with the latter serving as a part of the rocket pointing system control loop. Fabrication and alignment of the optical system is based on high precision machining and mechanical metrology techniques. The spectrograph has a resolution of 16 milliangstroms and modifications planned for future flights will improve the resolution to 5 milliangstroms, permitting line widths to be measured.

  10. Ultraviolet and X-ray Activity and Flaring on Low-Mass Exoplanet Host Stars

    NASA Astrophysics Data System (ADS)

    France, Kevin; Parke Loyd, R. O.; Brown, Alexander

    2015-08-01

    The spectral and temporal behavior of exoplanet host stars is a critical input to models of the chemistry and evolution of planetary atmospheres. High-energy photons (X-ray to NUV) from these stars regulate the atmospheric temperature profiles and photochemistry on orbiting planets, influencing the production of potential “biomarker” gases. We present results from the MUSCLES Treasury Survey, an ongoing study of time-resolved UV and X-ray spectroscopy of nearby M and K dwarf exoplanet host stars. This program uses contemporaneous Hubble Space Telescope and Chandra (or XMM) observations to characterize the time variability of the energetic radiation field incident on the habitable zones planetary systems at d < 15 pc. We find that all exoplanet host stars observed to date exhibit significant levels of chromospheric and transition region UV emission. M dwarf exoplanet host stars display 30 - 2000% UV emission line amplitude variations on timescales of minutes-to-hours. The relative flare/quiescent UV flux amplitudes on old (age > 1 Gyr) planet-hosting M dwarfs are comparable to active flare stars (e.g., AD Leo), despite their lack of flare activity at visible wavelengths. We also detect similar UV flare behavior on a subset of our K dwarf exoplanet host stars. We conclude that strong flares and stochastic variability are common, even on “optically inactive” M dwarfs hosting planetary systems. These results argue that the traditional assumption of weak UV fields and low flare rates on older low-mass stars needs to be revised.

  11. Surface roughness evaluation on mandrels and mirror shells for future X-ray telescopes

    NASA Astrophysics Data System (ADS)

    Sironi, Giorgia; Spiga, D.

    2008-07-01

    More X-ray missions that will be operating in near future, like particular SIMBOL-X, e-Rosita, Con-X/HXT, SVOM/XIAO and Polar-X, will be based on focusing optics manufactured by means of the Ni electroforming replication technique. This production method has already been successfully exploited for SAX, XMM and Swift-XRT. Optical surfaces for X-ray reflection have to be as smooth as possible also at high spatial frequencies. Hence it will be crucial to take under control microroughness in order to reduce the scattering effects. A high rms microroughness would cause the degradation of the angular resolution and loss of effective area. Stringent requirements have therefore to be fixed for mirror shells surface roughness depending on the specific energy range investigated, and roughness evolution has to be carefully monitored during the subsequent steps of the mirror-shells realization. This means to study the roughness evolution in the chain mandrel, mirror shells, multilayer deposition and also the degradation of mandrel roughness following iterated replicas. Such a study allows inferring which phases of production are the major responsible of the roughness growth and could help to find solutions optimizing the involved processes. The exposed study is carried out in the context of the technological consolidation related to SIMBOL-X, along with a systematic metrological study of mandrels and mirror shells. To monitor the roughness increase following each replica, a multiinstrumental approach was adopted: microprofiles were analysed by means of their Power Spectral Density (PSD) in the spatial frequency range 1000-0.01 μm. This enables the direct comparison of roughness data taken with instruments characterized by different operative ranges of frequencies, and in particular optical interferometers and Atomic Force Microscopes. The performed analysis allowed us to set realistic specifications on the mandrel roughness to be achieved, and to suggest a limit for the

  12. Hubble Space Telescope Imaging of Bright Galactic X-Ray Binaries in Crowded Fields

    NASA Technical Reports Server (NTRS)

    Deutsch, Eric W.; Margon, Bruce; Wachter, Stefanie; Anderson, Scott F.

    1996-01-01

    We report high spatial resolution HST imagery and photometry of three well-studied, intense Galactic X-ray binaries, X2129+470, CAL 87, and GX 17+2. All three sources exhibit important anomalies that are not readily interpreted by conventional models. Each source also lies in a severely crowded field, and in all cases the anomalies would be removed if much of the light observed from the ground in fact came from a nearby, thus far unresolved superposed companion. For V1727 Cyg (X2129+470), we find no such companion. We also present an HST FOS spectrum and broadband photometry which is consistent with a single, normal star. The supersoft LMC X-ray source CAL 87 was already known from ground-based work to have a companion separated by O.9 minutes from the optical counterpart; our HST images clearly resolve these objects and yield the discovery of an even closer, somewhat fainter additional companion. Our photometry indicates that contamination is not severe outside eclipse, where the companions only contribute 20% of the light in V, but during eclipse more than half of the V light comes from the companions. The previously determined spectral type of the CAL 87 secondary may need to be reevaluated due to this significant contamination, with consequences on inferences of the mass of the components. We find no companions to NP Ser (= X1813-14, = GX 17+2). However, for this object we point out a small but possibly significant astrometric discrepancy between the position of the optical object and that of the radio source which is the basis for the identification. This discrepancy needs to be clarified.

  13. 1SXPS: A Deep Swift X-Ray Telescope Point Source Catalog with Light Curves and Spectra

    NASA Technical Reports Server (NTRS)

    Evans, P. A.; Osborne, J. P.; Beardmore, A. P.; Page, K. L.; Willingale, R.; Mountford, C. J.; Pagani, C.; Burrows, D. N.; Kennea, J. A.; Perri, M.; Tagliaferri, G.; Gehrels, N.

    2013-01-01

    We present the 1SXPS (Swift-XRT point source) catalog of 151,524 X-ray point sources detected by the Swift-XRT in 8 yr of operation. The catalog covers 1905 sq deg distributed approximately uniformly on the sky. We analyze the data in two ways. First we consider all observations individually, for which we have a typical sensitivity of approximately 3 × 10(exp -13) erg cm(exp -2) s(exp -1) (0.3-10 keV). Then we co-add all data covering the same location on the sky: these images have a typical sensitivity of approximately 9 × 10(exp -14) erg cm(exp -2) s(exp -1) (0.3-10 keV). Our sky coverage is nearly 2.5 times that of 3XMM-DR4, although the catalog is a factor of approximately 1.5 less sensitive. The median position error is 5.5 (90% confidence), including systematics. Our source detection method improves on that used in previous X-ray Telescope (XRT) catalogs and we report greater than 68,000 new X-ray sources. The goals and observing strategy of the Swift satellite allow us to probe source variability on multiple timescales, and we find approximately 30,000 variable objects in our catalog. For every source we give positions, fluxes, time series (in four energy bands and two hardness ratios), estimates of the spectral properties, spectra and spectral fits for the brightest sources, and variability probabilities in multiple energy bands and timescales.

  14. A multi-frequency study of an X ray selected sample of active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Grossan, Bruce Alan

    1992-01-01

    The LASS (Large Area Sky Survey) experiment, which flew aboard the HEAO-1 spacecraft, carried out a 2-20 keV survey of the sky during 1977-1978. The X-ray sources from this survey make up the LASS catalog (Wood et al. 1979). Optical counterparts have been identified for greater than 86 percent of the LASS sources above a flux of approx. 0.95 microns (mu)Jy Q 5 keV (Remillard 1992b). The LASS error boxes, along with the more precise positions from the Modulation Collimator (MC) X-ray experiment (also aboard HEAO-1), subsequent X-ray imaging, and optical search techniques were all used to identify the LASS sources. From these identifications, a high-latitude (absolute value of b greater than 20 deg.), flux limited (greater than or equal to 0.95 (mu)Jy) sample of 96 emission line Active Galactic Nuclei (AGN) have been selected for study. The sample is referred to as the LMA (for the LASS/MC identified sample of AGN). The objective of this work is to produce multi-frequency spectra of this sample of objects, in order to determine and interpret the statistical properties of the sample over nearly the full range of observable wavelengths. Data were obtained for as much of the radio through hard X-ray (less than 20 keV) spectrum as possible for each object in the LMA. Radio, near infrared, and other measurements were taken from the literature, far IR fluxes were extracted from co-added observations from IRAS, UV spectra were obtained from the IUE archives, and original observations were performed (with the help of collaborators) in the radio, near IR, optical, UV, and X-ray to fulfill this goal. Correlation studies of the continuum bands found poor correlations of X-ray and radio flux, good correlations for 12 and 26 micron flux with X-ray flux, excellent correlations for optical and near IR fluxes with X-rays, and poor correlations of UV and X-ray fluxes. Correlation studies of the line and X-ray continuum flux yield a good correlation between the flux of (OIII), the

  15. The SPARX Project: R & D Activity Towards X-Rays FEL Sources

    SciTech Connect

    Alesini, D.; Bellaveglia, M.; Bertolucci, S.; Biagini, M.E.; Boni, R.; Boscolo, M.; Castellano, M.; Clozza, A.; Di Pirro, G.; Drago, A.; Esposito, A.; Ferrario, M.; Filippetto, D.; Fusco, V.; Gallo, A.; Ghigo, A.; Guiducci, S.; Incurvati, M.; Ligi, C.; Marcellini, F.; Migliorati, M.; /Frascati /ENEA, Frascati /INFN, Milan /INFN, Rome /INFN, Rome2 /Milan Polytechnic /UCLA /SLAC

    2005-08-05

    SPARX is an evolutionary project proposed by a collaboration among ENEA-INFN-CNR-Universita di Roma Tor Vergata aiming at the construction of a FELSASE X-ray source in the Tor Vergata Campus. The first phase of the SPARX project, funded by Government Agencies, will be focused on R&D activity on critical components and techniques for future X-ray facilities as described in this paper.

  16. Structure and stress studies of low temperature annealed W/Si multilayers for the X-ray telescope.

    PubMed

    Huang, Qiushi; Zhang, Jinshuai; Qi, Runze; Yang, Yang; Wang, Fengli; Zhu, Jie; Zhang, Zhong; Wang, Zhanshan

    2016-07-11

    Low stress W/Si multilayer mirrors are demanded in the hard X-ray telescopes to achieve the high angular resolution. To reduce the stress of the as-deposited multilayer and maintain a high reflectivity, two groups of low-temperature annealing experiments were performed on the periodic multilayers with a d-spacing of ~3.8 nm. The temperature-dependent experiments show that the 150 °C annealing can slightly increase the reflectivity while the stress reduced only by 24%. Higher temperature annealing induced a larger reduction of the stress and the multilayer reached an almost zero stress state at 250 °C. The stress relaxation was accompanied by a small drop of reflectivity of ≤5% and a period compaction of <0.02 nm. The time-dependent experiments indicate that most of the stress changes occurred within the first 10 minutes while a prolonged annealing is not useful. The X-ray scattering and transmission electron microscopy were further used to study the microstructure changes of the multilayers. It is found that the W/Si multilayer exhibits an amorphous structure before and after annealing, while an enhanced diffusion and intermixing is the main reason for the stress relaxation and structure changes.

  17. Get the Latest on the World's Most Powerful X-ray Telescope: NASA Experts Available to Talk About Chandra Observatory

    NASA Astrophysics Data System (ADS)

    1999-07-01

    Media Advisory: 99-142 You could read a newspaper from half a mile away or see a stop sign from 12 miles. That’s the kind of strength packed into the world’s most powerful X-ray telescope. Its name is the Chandra X-ray observatory and it starts a five-year mission this week when the Space Shuttle’s first female commander, Eileen Collins, and her crew release the new observatory from the Shuttle’s payload bay. Chandra is the largest and heaviest payload ever launched by the Space Shuttle. Using Chandra, scientists will learn more about black holes, study quasars at the edge of the universe, analyze comets in our solar system, and more. Get the story on NASA’s newest great observatory from the experts at the Operations Control Center in Cambridge, Mass. Who: Chandra Experts When: Beginning Tuesday evening, July 20 through July 27 Time: 6 - 10 a.m.; 6 - 10 p.m. EDT Satellite Windows: 10 minutes Satellite Interview Information: Robert Drake, Producer (256) 544-4139 (256) 544-1183 (PIN 0022) Story Information: Tim Tyson, Media Relations (256) 544-0034

  18. The prospects of X-ray polarimetry for Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Goosmann, René W.

    2016-08-01

    Polarimetry at optical and other wavelength continues to play an important role in our struggle to develop (super-)unification schemes for active galactic nuclei (AGN). Therefore, radio-loud and radio-quiet AGN are important targets for the future small and medium-size X-ray polarimetry missions that are currently under phase A study at NASA and ESA. After briefly pointing out the detection principle of polarization imaging in the soft X-ray band, I am going to review the prospects of X-ray polarimetry for our understanding of AGN ejection (winds and blazar jets) and accretion flows (accretion disk and corona). The X-ray polarimetry signal between 2 and 8 keV is going to give us important new constraints on the geometry of the central engine as well as on the acceleration effects in AGN jets, in particular when combined with spectral and/or polarization information at other wavelengths.

  19. An active contour method for bone cement reconstruction from C-arm x-ray images.

    PubMed

    Lucas, Blake C; Otake, Yoshito; Armand, Mehran; Taylor, Russell H

    2012-04-01

    A novel algorithm is presented to segment and reconstruct injected bone cement from a sparse set of X-ray images acquired at arbitrary poses. The sparse X-ray multi-view active contour (SxMAC-pronounced "smack") can 1) reconstruct objects for which the background partially occludes the object in X-ray images, 2) use X-ray images acquired on a noncircular trajectory, and 3) incorporate prior computed tomography (CT) information. The algorithm's inputs are preprocessed X-ray images, their associated pose information, and prior CT, if available. The algorithm initiates automated reconstruction using visual hull computation from a sparse number of X-ray images. It then improves the accuracy of the reconstruction by optimizing a geodesic active contour. Experiments with mathematical phantoms demonstrate improvements over a conventional silhouette based approach, and a cadaver experiment demonstrates SxMAC's ability to reconstruct high contrast bone cement that has been injected into a femur and achieve sub-millimeter accuracy with four images.

  20. Flight qualified solid argon cooler for the BBXRT instrument. [Broad Band X Ray Telescope for ASTRO-1 payload

    NASA Technical Reports Server (NTRS)

    Cygnarowicz, Thomas A.; Schein, Michael E.; Lindauer, David A.; Scarlotti, Roger; Pederson, Robert

    1990-01-01

    A solid argon cooler (SAC) for attached Shuttle payloads has been developed and qualified to meet the need for low cost cooling of flight instruments to the temperature range of 60-120 K. The SACs have been designed and tested with the intent of flying them up to five times. Two coolers, as part of the Broad Band X-ray Telescope (BBXRT) instrument on the ASTRO-1 payload, are awaiting launch on Space Shuttle mission STS-35. This paper describes the design, testing and performance of the SAC and its vacuum maintenance system (VMS), used to maintain the argon as a solid during launch delays of up to 5 days. BBXRT cryogen system design features used to satisfy Shuttle safety requirements are discussed, along with SAC ground servicing equipment (GSE) and procedures used to fill, freeze and subcool the argon.

  1. Model supporting the use of pressure in the hot slumping of glass substrates for X-ray telescopes.

    PubMed

    Salmaso, Bianca; Brizzolari, Claudia; Spiga, Daniele

    2016-10-17

    Thin glass foils are nowadays considered good substrates for lightweight focusing optics, especially for X-ray telescopes. The desired shape can be imparted to the foils by hot slumping, a process that replicates the shape of a slumping mould. During thermal slumping, when the glass and the mould come into contact, ripples in the glass surface appear spontaneously if the thermal expansions are mismatched. In our hot slumping setup, pressure is applied to ease the mould shape replication and to enhance the ripple relaxation. Starting from an existing model developed to explain the ripple formation in hot-slumped glass foils without pressure, we have developed a model that includes the pressure to support our experimental results.

  2. Design and fabrication of a supermirror with smooth and broad response for hard x-ray telescopes.

    PubMed

    Yao, Youwei; Kunieda, Hideyo; Matsumoto, Hironori; Tamura, Keisuke; Miyata, Yusuke

    2013-09-20

    We present our design and fabrication scheme of a supermirror for hard x-ray telescopes to improve the performance of reflection. Supermirrors are designed to achieve target reflectivity profiles with small ripples in the interesting energy range with a limited number of layer pairs. Starting from conventional design methods, we optimized the thickness distribution of the structure using a numerical approach with the merit function established for this application. As an example, a platinum-carbon supermirror structure of 123 layer pairs with a varying d-space of 2-6 nm was designed to enhance the reflectivity in the energy range from 11 to 55 keV with a flat top at a grazing angle of 0.28 deg. The multilayer thus designed was deposited on a float glass by our DC magnetron sputtering system. The reflectivity profile was successfully measured to be ~20% with little oscillation in all energy band of interest.

  3. [Build and Demonstrate a X-Ray Interferometer and Build and Fly a High Resolution Telescope on a Sounding Rocket}

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This report is written with eight months still go on the 36 month period of the grant. This grant, as originally proposed three years ago, was two pronged - to build and demonstrate a practical x-ray interferometer, and to build and fly a high resolution telescope on a sounding rocket. As we started into these projects, we received community feedback that led to our giving priority to the interferometer., The rocket would achieve O.2-arcsecond resolution that, while better, than that of Chandra, would, because of the limited signal of a sub-orbital flight, not be of substantially greater scientific use. The interferometry, on the other hand, shows the potential for many orders of magnitude improvement. For this reason we gave priority to the lab interferometry, and the building of the telescope lagged behind. With our new understanding (and practical demonstration) of how to build an interferometer, we changed the telescope design from spherical surfaces in the Kirkpatrick-Baez configuration, to an interferometer with resolution between .005 and .05 arcseconds.

  4. Simulated Solar Flare X-Ray and Thermal Cycling Durability Evaluation of Hubble Space Telescope Thermal Control Candidate Replacement Materials

    NASA Technical Reports Server (NTRS)

    deGroh, Kim K.; Banks, Bruce A.; Sechkar, Edward A.; Scheiman, David A.

    1998-01-01

    During the Hubble Space Telescope (HST) second servicing mission (SM2), astronauts noticed that the multilayer insulation (MLI) covering the telescope was damaged. Large pieces of the outer layer of MLI (aluminized Teflon fluorinated ethylene propylene (Al-FEP)) were torn in several locations around the telescope. A piece of curled up Al-FEP was retrieved by the astronauts and was found to be severely embrittled, as witnessed by ground testing. Goddard Space Flight Center (GSFC) organized a HST MLI Failure Review Board (FRB) to determine the damage mechanism of FEP in the HST environment, and to recommend replacement insulation material to be installed on HST during the third servicing mission (SM3) in 1999. Candidate thermal control replacement materials were chosen by the FRB and tested for environmental durability under various exposures and durations. This paper describes durability testing of candidate materials which were exposed to charged particle radiation, simulated solar flare x-ray radiation and thermal cycling under load. Samples were evaluated for changes in solar absorptance and tear resistance. Descriptions of environmental exposures and durability evaluations of these materials are presented.

  5. Analysis of the relative movement between mirrors and detectors for the next generation x-ray telescopes

    NASA Astrophysics Data System (ADS)

    Civitani, Marta

    2009-08-01

    Focusing X-ray telescopes with imaging capabilities, like SIMBOL-X, HEXISAT and IXO, are characterized by very long focal lengths, greater than 10m. The constraints posed by the launchers on the maximum dimensions of a payload, make necessary using alternatives to monolithic telescopes. One possibility is that the mirror and the detectors are carried by two separate spacecrafts that fly in formation. Another is placing the detector module on a bench that will be extended once in final orbit. In both the case the system will be subjected to deformation due the relative movement of the mirrors with respect to detectors. In one case the deformation will be due to the correction on the position and attitude of the detector spacecraft to maintain the formation with the mirror spacecraft, while in the other to oscillations of the detectors on the top of the bench. The aim of this work is to compare the behavior of the system in the two different configurations and to evaluate the performances of the on board metrology systems needed not to degrade the telescope angular resolution.

  6. X-Ray Emission from Active Galactic Nuclei with Intermediate-Mass Black Holes

    NASA Astrophysics Data System (ADS)

    Dewangan, G. C.; Mathur, S.; Griffiths, R. E.; Rao, A. R.

    2008-12-01

    We present a systematic X-ray study of eight active galactic nuclei (AGNs) with intermediate-mass black holes (MBH ~ 8-95 × 104 M⊙) based on 12 XMM-Newton observations. The sample includes the two prototype AGNs in this class—NGC 4395 and POX 52 and six other AGNs discovered with the Sloan Digitized Sky Survey. These AGNs show some of the strongest X-ray variability, with the normalized excess variances being the largest and the power density break timescales being the shortest observed among radio-quiet AGNs. The excess-variance-luminosity correlation appears to depend on both the BH mass and the Eddington luminosity ratio. The break timescale-black hole mass relations for AGN with IMBHs are consistent with that observed for massive AGNs. We find that the FWHM of the Hβ/Hα line is uncorrelated with the BH mass, but shows strong anticorrelation with the Eddington luminosity ratio. Four AGNs show clear evidence for soft X-ray excess emission (kTin ~ 150-200 eV). X-ray spectra of three other AGNs are consistent with the presence of the soft excess emission. NGC 4395 with lowest L/LEdd lacks the soft excess emission. Evidently small black mass is not the primary driver of strong soft X-ray excess emission from AGNs. The X-ray spectral properties and optical-to-X-ray spectral energy distributions of these AGNs are similar to those of Seyfert 1 galaxies. The observed X-ray/UV properties of AGNs with IMBHs are consistent with these AGNs being low-mass extensions of more massive AGNs, those with high Eddington luminosity ratio looking more like narrow-line Seyfert 1 s and those with low L/LEdd looking more like broad-line Seyfert 1 galaxies.

  7. Long-term X-Ray Variability of Typical Active Galactic Nuclei in the Distant Universe

    NASA Astrophysics Data System (ADS)

    Yang, G.; Brandt, W. N.; Luo, B.; Xue, Y. Q.; Bauer, F. E.; Sun, M. Y.; Kim, S.; Schulze, S.; Zheng, X. C.; Paolillo, M.; Shemmer, O.; Liu, T.; Schneider, D. P.; Vignali, C.; Vito, F.; Wang, J.-X.

    2016-11-01

    We perform long-term (≈15 years, observed-frame) X-ray variability analyses of the 68 brightest radio-quiet active galactic nuclei (AGNs) in the 6 Ms Chandra Deep Field-South survey; the majority are in the redshift range of 0.6-3.1, providing access to penetrating rest-frame X-rays up to ≈10-30 keV. Of the 68 sources, 24 are optical spectral type I AGNs, and the rest (44) are type II AGNs. The timescales probed in this work are among the longest for X-ray variability studies of distant AGNs. Photometric analyses reveal widespread photon flux variability: 90% of AGNs are variable above a 95% confidence level, including many X-ray obscured AGNs and several optically classified type II quasars. We characterize the intrinsic X-ray luminosity ({L}{{X}}) and absorption ({N}{{H}}) variability via spectral fitting. Most (74%) sources show {L}{{X}} variability; the variability amplitudes are generally smaller for quasars. A Compton-thick candidate AGN shows variability of its high-energy X-ray flux, indicating the size of reflecting material to be ≲0.3 pc. {L}{{X}} variability is also detected in a broad absorption line quasar. The {N}{{H}} variability amplitude for our sample appears to rise as time separation increases. About 16% of sources show {N}{{H}} variability. One source transitions from an X-ray unobscured to obscured state, while its optical classification remains type I; this behavior indicates the X-ray eclipsing material is not large enough to obscure the whole broad-line region.

  8. The BeppoSAX View of the X-Ray Active Nucleus of NGC 4258

    NASA Astrophysics Data System (ADS)

    Fiore, F.; Pellegrini, S.; Matt, G.; Antonelli, L. A.; Comastri, A.; della Ceca, R.; Giallongo, E.; Mathur, S.; Molendi, S.; Siemiginowska, A.; Trinchieri, G.; Wilkes, B.

    2001-07-01

    BeppoSAX observed the Seyfert 1.9 galaxy NGC 4258 in 1998 December, when its 2-10 keV luminosity was about 1041 ergs s-1. Large amplitude (100%) variability is observed in the 3-10 keV band on timescales of a few tens of thousands of seconds, while variability of ~20% is observed on timescales as short as 1 hr. The nuclear component is visible above 2 keV only, being obscured by a column density of (9.5+/-1.2)×1022 cm-2 this component is detected at up to 70 keV with a signal-to-noise ratio of >~3 and with a steep power-law energy spectral index of αE=1.11+/-0.14. Bremsstrahlung emission for the 2-70 keV X-ray luminosity, as expected in advection-dominated accretion flow models with strong winds, is ruled out by the data. The ratio between the nuclear radio (22 GHz) luminosity and the X-ray (5 keV) luminosity is consistent with that of radio-quiet quasars and Seyfert galaxies. X-ray variability, spectral shape, and radio/X-ray and near-IR/X-ray luminosity ratios suggest that the nucleus of NGC 4258 could be a scaled down version of a Seyfert nucleus and that the X-ray nuclear luminosity can be explained in terms of Comptonization in a hot corona. The soft (E<~2 keV) X-ray emission is complex. There are at least two thermal-like components with temperatures of 0.6+/-0.1 keV and >~1.3 keV. The cooler (L0.1-2.4keV~1040 ergs s-1) component is probably associated with the jet, resolved in X-rays by the ROSAT HRI (Cecil et al. 1994). The luminosity of the second component, which can be modeled equally well by an unobscured power-law model with αE=0.2+0.8-0.2, is L0.1-2.4keV~7×1039 ergs s-1, consistent with that expected from discrete X-ray sources (binaries and supernova remnants) in the host galaxy. Observations of NGC 4258 and other maser active galactic nuclei (AGNs) show strong nuclear X-ray absorption. We propose that this large column of gas might be responsible for shielding the regions of water maser emission from X-ray illumination. So a large column density

  9. Analysis of nearly simultaneous X-ray and optical observations of active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Webb, James Raymond

    Rosemary Hill optical and EINSTEIN X-ray observations of a sample of 36 active galactic nuclei (AGN) were reduced and analyzed. Seventy-two X-ray observations of these sources were reduced, nineteen of which yielded spectral information. Of these spectral observations, significant hydrogen column densities above the galactic value were required for nine of the eleven sources which were observed more than once by EINSTEIN. Correlations between the X-ray and optical luminosities were investigated using the Jefferys method of least squares. This method allows for errors in both variables. The results indicate a strong correlation between the X-ray and optical luminosities for the entire sample. Division of the sample into groups with similar optical variability characteristics show that the less violently violent variable AGN are more highly correlated than the violently variable blazars. Infrared and radio observations were combined with the X-ray and optical observations of six AGN. These sources were modelled in terms of the synchrotron-self-Compton model. The turnover frequency falls between the infrared and radio data and reliable estimates of this parameter are difficult to estimate. Therefore the results were found as a function of the turnover frequency. Four sources required relativistic bulk motion or beaming. Multifrequency spectra made at different times for one individual source, 0235+164, required different amounts of beaming to satisfy the X-ray observations. Sizes of the emitting regions for the sources modelled ranged from 0.5 parsec to 1.0 parsec.

  10. Development of high angular resolution x-ray telescopes based on slumped glass foils

    NASA Astrophysics Data System (ADS)

    Ghigo, M.; Basso, S.; Borsa, F.; Citterio, O.; Civitani, M.; Conconi, P.; Pagano, G.; Pareschi, G.; Proserpio, L.; Salmaso, B.; Sironi, G.; Spiga, D.; Tagliaferri, G.; Zambra, A.; Parodi, G.; Martelli, F.; Gallieni, D.; Tintori, M.; Bavdaz, M.; Wille, E.

    2012-09-01

    The mirrors of the International X-ray Observatory (IXO) were based on a large number of high quality segments, aiming at achieving a global spatial resolution better than 5” HEW while giving a large collecting area (around 3m2@ 1 keV). A study concerning the hot slumping of thin glass foils was started in Europe, funded by ESA and led by the Brera Astronomical Observatory (INAF-OAB), for the development of a replication technology based on glass material. The study is currently continuing even after the IXO program has been descoped and renamed ATHENA, in the perspective of using the technology under development for other future missions or applications. INAF-OAB efforts have been focused on the "Direct" slumping approach with convex moulds, meaning that during the thermal cycle the optical surface of the glass is in direct contact with the mould surface. The single mirror segments are made of thin glass plates (0.4 mm thick), with a reflecting area of 200 mm × 200 mm. The adopted integration process foresees the use of glass reinforcing ribs for bonding together the plates in such a way to form a rigid and stiff stack of segmented mirror shells; the stack is supported by a thick backplane. During the bonding process, the plates are constrained in close contact with the surface of a precisely figured integration master by the application of vacuum pump suction. In this way, the springback deformations and the low frequency errors still present in the plates' profile after slumping can be corrected. The status of the technology development is presented in this paper, together with the description and metrology of the prototypes already realized or under construction at the Observatory laboratories.

  11. Liquid metal actuators: correctable mounting and assembly of thin-shell x-ray telescope mirrors

    NASA Astrophysics Data System (ADS)

    Bruccoleri, Alexander R.; Klingensmith, Martin; Chalifoux, Brandon; Heilmann, Ralf K.; Schattenburg, Mark L.

    2015-09-01

    An ideal bonding agent for thin-shell x-ray mirrors could be quickly applied to joints and set with deterministic and stable properties. Unfortunately, mirror assembly methods have typically utilized various epoxy formulations which are messy, slow to apply and cure, and far from deterministic or stable. Problems include shrinkage, creep and high thermal and humidity sensitivity. Once the bond is set errors are frozen in and cannot be corrected. We are developing a new method for bonding thin-foil mirrors that has the potential to solve these problems. Our process to bond mirrors to housing reference points is achieved via small beads of a low-melting-point bonding agent (such as solder or thermoset). The mirror is bonded to small contact surface points under real-time metrology. If the position of the mirror needs to be adjusted after bonding, a small force is applied normal or parallel to the contact surface and a pulsed fiber laser is used to melt an ultrathin layer of the solder for a very short time. The joint is then compressed, stretched or sheared while molten before refreezing in a new position, enabling repeatable and stable mirror position adjustments along the direction of the force in nm-level steps with minimal heat input. We present results from our prototype apparatus demonstrating proof of principle. The initial experiment includes developing a technique to bond D263 glass to Kovar, designing and building a one-dimensional stage to precisely apply force, and using an infrared laser pulse to heat the joint while measuring position and force.

  12. Multi-Spectral Solar Telescope Array. IV - The soft X-ray and extreme ultraviolet filters

    NASA Technical Reports Server (NTRS)

    Lindblom, Joakim F.; O'Neal, Ray H.; Walker, Arthur B. C., Jr.; Powell, Forbes R.; Barbee, Troy W., Jr.; Hoover, Richard B.

    1991-01-01

    NASA's Multi-Spectral Solar Telescope Array uses various combinations of thin foil filters composed of Al, C, Te, Be, Mo, Rh, and phthalocyanine to achieve the requisite radiation-rejection characteristics. Such rejection is demanded by the presence of strong EUV radiation at longer wavelengths where the specular reflectivity of multilayer mirrors can cause 'contamination' of the image in the narrow band defined by the Bragg condition.

  13. Minimalist coupled evolution model for stellar X-ray activity, rotation, mass loss, and magnetic field

    NASA Astrophysics Data System (ADS)

    Blackman, Eric G.; Owen, James E.

    2016-05-01

    Late-type main-sequence stars exhibit an X-ray to bolometric flux ratio that depends on {tilde{R}o}, the ratio of rotation period to convective turnover time, as {tilde{R}o}^{-ζ } with 2 ≤ ζ ≤ 3 for {tilde{R}o} > 0.13, but saturates with |ζ| < 0.2 for {tilde{R}o} < 0.13. Saturated stars are younger than unsaturated stars and show a broader spread of rotation rates and X-ray activity. The unsaturated stars have magnetic fields and rotation speeds that scale roughly with the square root of their age, though possibly flattening for stars older than the Sun. The connection between faster rotators, stronger fields, and higher activity has been established observationally, but a theory for the unified time-evolution of X-ray luminosity, rotation, magnetic field and mass loss that captures the above trends has been lacking. Here we derive a minimalist holistic framework for the time evolution of these quantities built from combining a Parker wind with new ingredients: (1) explicit sourcing of both the thermal energy launching the wind and the X-ray luminosity via dynamo produced magnetic fields; (2) explicit coupling of X-ray activity and mass-loss saturation to dynamo saturation (via magnetic helicity build-up and convection eddy shredding); (3) use of coronal equilibrium to determine how magnetic energy is divided into wind and X-ray contributions. For solar-type stars younger than the Sun, we infer conduction to be a subdominant power loss compared to X-rays and wind. For older stars, conduction is more important, possibly quenching the wind and reducing angular momentum loss. We focus on the time evolution for stars younger than the Sun, highlighting what is possible for further generalizations. Overall, the approach shows promise towards a unified explanation of all of the aforementioned observational trends.

  14. ProtoEXIST: The Development of Advanced Tiled CZT Detector Planes for Wide Field Hard X-Ray Survey Telescope

    NASA Astrophysics Data System (ADS)

    Allen, Branden; Hong, J.; Grindlay, J.; Barthelmy, S.; Baker, R.

    2011-05-01

    ProtoEXIST is a technology development program for a coded aperture hard X-ray telescope with a large area (1-5 m^2) CZT detector plane for use in a future hard X-ray wide field sky monitor and survey telescope. The successful flight of the ProtoEXIST1 (P1) coded-aperture telescope concluded the first phase of the program on October 9, 2009. The black hole binary Cyg X-1 was imaged and its spectrum measured at the end of the (6h) flight. The P1 detector plane is comprised of a 8x8 array of detector crystal units (DCUs); each made up of a single 20 mm x 20 mm, 5 mm thick Redlen CZT crystal with a 8x8 pixilated anode (pixel pitch of 2.5 mm) bonded to an interposer board connecting each of the individual 64 anode pixels to a single input channel on a RadNET ASIC, forming a 256 cm^2 contiguous CZT imaging array with 4096 individual pixels. P1 was successfully recovered and has undergone further characterization in the interim. The program continues with the ongoing development ProtoEXIST2 (P2) utilizing a closely tiled 8x8 array of DCUs now with a reduced anode pixel pitch of 0.6 mm. Each DCU in P2 will consist of a CZT crystal, identical to that utilized in P1 now with a 32x32 pixelated anode, directly bonded to a single NuSTAR ASIC (Nu-ASIC). The fully assembled P2 imaging detector will be comprised of a semi-contiguous 256x256 array of pixels on 256 cm^2 of CZT. With its finer pixelation the P2 detector plane will enable 5' (FWHM) imaging with a 70 cm focal length and will be flown side-by-side with P1 from Ft. Sumner in the Spring of 2012. Results from the characterization of the P1 detector are discussed as well as current progress in the development of the P2 detector plane.

  15. [The antioxidant enzyme activity in mouse liver mitochondria after nanosecond pulsed periodic X-ray exposure].

    PubMed

    Kniazeva, I R; Ivanov, V V; Bol'shakov, M A; Zharkova, L P; Kereia, A V; Kutenkov, O P; Rostov, V V

    2013-01-01

    The effect of repetitive pulsed X-ray (4 ns pulse duration, 300 kV accelerating voltage; 2.5 kA electron beam current) on the antioxidant enzyme activity in mouse liver mitochondria has been investigated. The mitochondrial suspension was exposed to single 4000 pulse X-ray radiation with repetition rates ranging between 10 and 22 pps (pulsed dose was 0.3-1.8 x 10(-6) Gy/pulse, the total absorbed dose following a single exposure was 7.2 x 10(-3) Gy). It was shown that a short-time exposure to X-ray radiation changes the antioxidant enzyme activity in mouse liver mitochondria. The greatest effect was observed in the changes of the activity of the metal-containing enzymes: superoxide dismutase and glutathione peroxidase. The effect depends on the pulse repetition frequency and radiation dose.

  16. X-ray flux variability of active galactic nuclei observed using NuSTAR

    NASA Astrophysics Data System (ADS)

    Rani, Priyanka; Stalin, C. S.; Rakshit, Suvendu

    2017-04-01

    We present results of a systematic study of flux variability on hourly time-scales in a large sample of active galactic nuclei (AGN) in the 3-79 keV band using data from Nuclear Spectroscopic Telescope Array. Our sample consists of four BL Lac objects (BL Lacs), three flat spectrum radio quasars (FSRQs) 24 Seyfert 1, 42 Seyfert 2 and eight narrow line Seyfert 1 (NLSy1) galaxies. We find that in the 3-79 keV band, about 65 per cent of the sources in our sample show significant variations on hourly time-scales. Using the Mann-Whitney U-test and the Kolmogorov-Smirnov test, we find no difference in the variability behaviour between Seyfert 1 and 2 galaxies. The blazar sources (FSRQs and BL Lacs) in our sample are more variable than Seyfert galaxies that include Seyfert 1 and Seyfert 2 in the soft (3-10 keV), hard (10-79 keV) and total (3-79 keV) bands. NLSy1 galaxies show the highest duty cycle of variability (87 per cent), followed by BL Lacs (82 per cent), Seyfert galaxies (56 per cent) and FSRQs (23 per cent). We obtained flux doubling/halving time in the hard X-ray band less than 10 min in 11 sources. The flux variations between the hard and soft bands in all the sources in our sample are consistent with zero lag.

  17. Analysis of nearly simultaneous x-ray and optical observations of active galactic nuclei

    SciTech Connect

    Webb, J.R.

    1988-01-01

    Rosemary Hill optical and EINSTEIN X-ray observations of a sample of 36 galactic nuclei (AGN) were reduced and analyzed. Seventy-two x-ray observations of these sources were reduced, nineteen of which yielded spectral information. Of these spectra observations, significant hydrogen column densities above the galactic value were required for nine of the active galactic nuclei. X-ray variability was detected in eight of the eleven sources which were observed more than once by EINSTEIN. Correlations between the x-ray and optical luminosities were investigated using the Jefferys method of least squares. This method allows for errors in both variables. The results indicate a strong correlation between the x-ray and optical luminosities for the entire sample. Division of the sample into groups with similar optical variability characteristics show that the less violently violent variable AGN are more highly correlated than the violently variable blazars. Infrared and radio observations were combined with the x-ray and optical observations of six AGN. These sources were modelled in terms of the synchrotron-self-Compton model. The turnover frequency falls between the infrared and radio data and reliable estimates of this parameter are difficult to estimate. Therefore the results were found as a function of the turnover frequency. Four sources required relativistic bulk motion or beaming. Multifrequency spectra made at different times for one individual source, 0235+164, required different amounts of beaming to satisfy the x-ray observations. Sizes of the emitting regions for the sources modelled ranged from 0.5 parsec to 1.0 parsec.

  18. DIRECT MEASUREMENT OF THE X-RAY TIME-DELAY TRANSFER FUNCTION IN ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Legg, E.; Miller, L.; Turner, T. J.; Giustini, M.; Reeves, J. N.; Kraemer, S. B.

    2012-11-20

    The origin of the observed time lags, in nearby active galactic nuclei (AGNs), between hard and soft X-ray photons is investigated using new XMM-Newton data for the narrow-line Seyfert I galaxy Ark 564 and existing data for 1H 0707-495 and NGC 4051. These AGNs have highly variable X-ray light curves that contain frequent, high peaks of emission. The averaged light curve of the peaks is directly measured from the time series, and it is shown that (1) peaks occur at the same time, within the measurement uncertainties, at all X-ray energies, and (2) there exists a substantial tail of excess emission at hard X-ray energies, which is delayed with respect to the time of the main peak, and is particularly prominent in Ark 564. Observation (1) rules out that the observed lags are caused by Comptonization time delays and disfavors a simple model of propagating fluctuations on the accretion disk. Observation (2) is consistent with time lags caused by Compton-scattering reverberation from material a few thousand light-seconds from the primary X-ray source. The power spectral density and the frequency-dependent phase lags of the peak light curves are consistent with those of the full time series. There is evidence for non-stationarity in the Ark 564 time series in both the Fourier and peaks analyses. A sharp 'negative' lag (variations at hard photon energies lead soft photon energies) observed in Ark 564 appears to be generated by the shape of the hard-band transfer function and does not arise from soft-band reflection of X-rays. These results reinforce the evidence for the existence of X-ray reverberation in type I AGN, which requires that these AGNs are significantly affected by scattering from circumnuclear material a few tens or hundreds of gravitational radii in extent.

  19. Performance analysis of grazing incidence imaging systems. [X ray telescope aberrations

    NASA Technical Reports Server (NTRS)

    Winkler, C. E.; Korsch, D.

    1977-01-01

    An exact expression relating the coordinates of a point on the incident ray, a point of reflection from an arbitrary surface, and a point on the reflected ray is derived. The exact relation is then specialized for the case of grazing incidence, and first order and third order systematic analyses are carried out for a single reflective surface and then for a combination of two surfaces. The third order treatment yields a complete set of primary aberrations for single element and two element systems. The importance of a judicious choice for a coordinate system in showing field curvature to clearly be the predominant aberration for a two element system is discussed. The validity of the theory is verified through comparisons with the exact ray trace results for the case of the telescope.

  20. Effects of diffraction in multiple-grid telescopes for X-ray astronomy

    NASA Technical Reports Server (NTRS)

    Lindsey, C. A.

    1978-01-01

    Diffraction effects in modern designs for grid collimator telescopes (assumed to have roughly a 100-micron grid period) are apparent at wavelengths longer than 1 A and are dominant at wavelengths longer than 10 A. In collimators with many grids spaced far apart the effects of diffracation are to reduce strongly the peak transmission of the collimator at longer wavelengths and to broaden it by about the amount expected from Fraunhofer diffraction through a slit the size of the grid openings. Comparisons between two-collimator measurements and the present calculations show reasonable agreement; it is therefore concluded that the present single-collimator calculation gives a good representation of their diffraction-limited angular response.

  1. An Extensive Census of Hubble Space Telescope Counterparts to Chandra X-Ray Sources in the Globular Cluster 47 Tucanae. II. Time Series and Analysis

    NASA Astrophysics Data System (ADS)

    Edmonds, Peter D.; Gilliland, Ronald L.; Heinke, Craig O.; Grindlay, Jonathan E.

    2003-10-01

    ) studies by Albrow et al. The X-ray properties of these objects (luminosity, hardness ratios, and variability) are consistent with those of active binaries found in field studies, and the FX/Fopt distribution is significantly different from those of the CVs and the MSPs that are detected (or possibly detected) in the optical. Despite these results, we examine the possibility that a few of the active binaries are MSPs with main-sequence companions resulting from double exchanges in the crowded core of 47 Tuc. No solid evidence is found for a significant population of such objects, and therefore, using the methods of Grindlay et al., we estimate that the number of MSPs in 47 Tuc with luminosities above 1030 ergs s-1 is ~30-40, near the previous lower limit. We present the results of a new, deeper search for faint low-mass X-ray binaries (LMXBs) in quiescence. One reasonable and one marginal candidate for optical identification of a quiescent LMXB was found (one is already known). Finally, it is shown that the periods of the blue variables showing little or no evidence for X-ray emission are too long for Roche lobe filling (if the variations are ellipsoidal). These blue variables also show no evidence for the large flickering levels seen in comparably bright CVs. At present we have no satisfactory explanation for these objects, although some may be detached white dwarf-main-sequence star binaries. Based on observations with the NASA/ESA Hubble Space Telescope obtained at STScI, which is operated by AURA, Inc. under NASA contract NAS 5-26555.

  2. Thermal Analysis of Next-Generation Space Telescope (NGST) Mirrors During Optical Testing in the X-Ray Calibration Facility (XRCF)

    NASA Technical Reports Server (NTRS)

    Page, Tim; Sutherlin, Steven

    2002-01-01

    This paper presents Thermal Analysis of the Next Generation Space Telescope (NGST) Mirrors During Optical Testing in the X-Ray Calibration Facility (XRCF). The contents include: 1) NGST Spacecraft Concept; 2) NGST Mirror Development Testing; 3) NGST Development Mirror; 4) Knudsen Number; 5) Free-Molecular Conduction; 6) Accomodation Coefficient; and 7) Results and Recommendations. This paper is presented in viewgraph form.

  3. The increasing X-Ray Activity of PKS 2155-304

    NASA Astrophysics Data System (ADS)

    Kapanadze, Bidzina

    2016-10-01

    The southern TeV-detected HBL source PKS 2155-304 (z=0.116) is prominent with its very strong TeV/X-ray flaring behaviour (see, e.g., Aharonian et al. 2009, A & A, 502, 749; Abramowski et al. 2012, A & A, 539; Kapanadze et al. 2014, MNRAS, 444; 1076), and, therefore, it represents one of the frequent Swift targets (203 observations since 2005 November 17). In the framework of our Target of Opportunity (ToO) request Number 8344, the source was pointed nine time by X-Ray Telescope onboard the Swift satellite (Swift-XRT) since 2016 August 5 with one week intervals between the successive observations.

  4. Activity of psoralen-functionalized nanoscintillators against cancer cells upon X-ray excitation.

    PubMed

    Scaffidi, Jonathan P; Gregas, Molly K; Lauly, Benoit; Zhang, Yan; Vo-Dinh, Tuan

    2011-06-28

    We report development of a nanoparticle-based, X-ray-activated anticancer "nanodrug" composed of yttrium oxide (Y(2)O(3)) nanoscintillators, a fragment of the HIV-1 TAT peptide, and psoralen. In this formulation, X-ray radiation is absorbed by the Y(2)O(3) nanoscintillators, which then emit UVA light. Absorption of UVA photons by nanoparticle-tethered psoralen has the potential to cross-link adenine and thymine residues in DNA. UVA-induced cross-linking by free psoralen upon activation with UVA light has previously been shown to cause apoptosis in vitro and an immunogenic response in vivo. Studies using the PC-3 human prostate cancer cell line demonstrate that X-ray excitation of these psoralen-functionalized Y(2)O(3) nanoscintillators yields concentration-dependent reductions in cell number when compared to control cultures containing psoralen-free Y(2)O(3) nanoscintillators.

  5. Water maser emission from X-ray-heated circumnuclear gas in active galaxies

    NASA Technical Reports Server (NTRS)

    Neufeld, David A.; Maloney, Philip R.; Conger, Sarah

    1994-01-01

    We have modeled the physical and chemical conditions present within dense circumnuclear gas that is irradiated by X-rays from an active galactic nucleus. Over a wide range of X-ray fluxes and gas pressures, the effects of X-ray heating give rise to a molecular layer at temperatures of 400-1000 K within which the water abundance is large. The physical conditions within this molecular layer naturally give rise to collisionally pumped maser emission in the 6(sub 16) - 5(sub 23) 22 GHz transition of ortho-water, with predicted maser luminosities of 10(exp 2 +/- 0.5) solar luminosity per sq. pc of illuminated area. Given plausible assumptions about the geometry of the source and about the degree to which the maser emission is anisotropic, such surface luminosities are sufficient to explain the large apparent luminosities observed in water maser sources that are associated with active galactic nuclei.

  6. The birthplaces of active regions and X-ray bright points. [on sun

    NASA Technical Reports Server (NTRS)

    Howard, R.; Fritzova-Svestkova, L.; Svestka, Z.

    1979-01-01

    A comparison of soft X-ray pictures of the Sun (S-054 experiment of Skylab) with K-line spectroheliograms (Mount Wilson) shows that the X-ray bright points tend to emerge randomly throughout the Ca network pattern. However, all those bright points that developed into active regions emerged at the boundaries of network cells. This suggests that the magnetic flux of active regions comes from greater depths in the convection zone that the shallow flux that gives rise to the random emergence of bright points.

  7. Ultraviolet and X-ray variability of active galactic nuclei with Swift

    NASA Astrophysics Data System (ADS)

    Buisson, D. J. K.; Lohfink, A. M.; Alston, W. N.; Fabian, A. C.

    2017-01-01

    We analyse a sample of 21 active galactic nuclei using data from the Swift satellite to study the variability properties of the population in the X-ray, UV and optical band. We find that the variable part of the UV-optical emission has a spectrum consistent with a power law, with an average index of -2.21 ± 0.13, as would be expected from central illumination of a thin disc (index of -7/3). We also calculate the slope of a power law from UV to X-ray variable emission, αOX, Var; the average for this sample is αOX, Var = -1.06 ± 0.04. The anticorrelation of αOX with the UV luminosity, LUV, previously found in the average emission is also present in the variable part: αOX, Var = ( - 0.177 ± 0.083)log (Lν, Var(2500 Å)) + (3.88 ± 2.33). Correlated variability between the emission in X-rays and UV is detected significantly for 9 of the 21 sources. All these cases are consistent with the UV lagging the X-rays, as would be seen if the correlated UV variations were produced by the reprocessing of X-ray emission. The observed UV lags are tentatively longer than expected for a standard thin disc.

  8. X-ray crystal structure of divalent metal-activated ß-xyloisdase, RS223BX

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report the first X-ray structure of a glycoside hydrolase family 43 ß-xylosidase, RS223BX, which is strongly activated by the addition of divalent metal cations. The 2.69 Å structure reveals that the Ca2+ cation is located at the back of the active site pocket. The Ca2+ coordinates to H274 to sta...

  9. Ray tracing simulations for the wide-field x-ray telescope of the Einstein Probe mission based on Geant4 and XRTG4

    NASA Astrophysics Data System (ADS)

    Zhao, Donghua; Zhang, Chen; Yuan, Weimin; Willingale, Richard; Ling, Zhixing; Feng, Hua; Li, Hong; Ji, Jianfeng; Wang, Wenxin; Zhang, Shuangnan

    2014-07-01

    Einstein Probe (EP) is a proposed small scientific satellite dedicated to time-domain astrophysics working in the soft X-ray band. It will discover transients and monitor variable objects in 0.5-4 keV, for which it will employ a very large instantaneous field-of-view (60° × 60°), along with moderate spatial resolution (FWHM ˜ 5 arcmin). Its wide-field imaging capability will be achieved by using established technology in novel lobster-eye optics. In this paper, we present Monte-Carlo simulations for the focusing capabilities of EP's Wide-field X-ray Telescope (WXT). The simulations are performed using Geant4 with an X-ray tracer which was developed by cosine (http://cosine.nl/) to trace X-rays. Our work is the first step toward building a comprehensive model with which the design of the X-ray optics and the ultimate sensitivity of the instrument can be optimized by simulating the X-ray tracing and radiation environment of the system, including the focal plane detector and the shielding at the same time.

  10. Thin fused silica optics for a few arcsec angular resolution and large collecting area x-ray telescope

    NASA Astrophysics Data System (ADS)

    Citterio, O.; Civitani, M. M.; Pareschi, G.; Basso, S.; Campana, S.; Conconi, P.; Ghigo, M.; Mattaini, E.; Moretti, A.; Parodi, G.; Tagliaferri, G.

    2013-09-01

    The implementation of a X-ray mission with high imaging capabilities, similar to those achieved with Chandra (< 1 arcsec Half Energy Width, HEW), but with a much larger throughput is a very attractive perspective, even if challenging. For such a mission the scientific opportunities, in particular for the study of the early Universe, would remain at the state of the art for the next decades. At the beginning of the new millennium the XEUS mission has been proposed, with an effective area of several m2 and an angular resolution better than 2 arcsec HEW. Unfortunately, after the initial study, this mission was not implemented, mainly due to the costs and the low level of technology readiness. Currently the most advanced proposal for such a kind of mission is the SMART-X project, led by CfA and involving several other US Institutes. This project is based on adjustable segments of thin foil mirrors with piezo-electric actuators, aiming to achieve an effective area < 2 m2 at 1 keV and an angular resolution better than 1 arcsec HEW. Another attractive technology to realize an X-ray telescope with similar characteristics is being developed at NASA/Goddard. In this case the mirrors are based on Si substrates that are super-polished and figured starting from a bulky Si ingot, from which they are properly cut. Here we propose an alternative method based on precise direct grinding, figuring and polishing of thin (a few mm) glass shells with innovative deterministic polishing methods. This is followed by a final correction via ion figuring to obtain the desired accuracy in order to achieve the 1 arc sec HEW requirement. For this purpose, a temporary stiffening structure is used to support the shell from the polishing operations up to its integration in the telescope supporting structure. We will present the technological process under development, the results achieved so far and some mission scenarios based on this kind of optics, aiming to achieve an effective area more than

  11. Thin fused silica optics for a high angular resolution and large collecting area X Ray telescope after Chandra

    NASA Astrophysics Data System (ADS)

    Pareschi, Giovanni; Citterio, Oberto; Civitani, Marta M; Basso, Stefano; Campana, Sergio; Conconi, Paolo; Ghigo, Mauro; Mattaini, Enrico; Moretti, Alberto; Parodi, Giancarlo; Tagliaferri, Gianpiero

    2014-08-01

    The implementation of an X-ray mission with high imaging capabilities, similar to those achieved with Chandra (<1 arcsec Half Energy Width, HEW), but with a much larger throughput is very attractive, even if challenging. For such a mission the scientific opportunities, in particular for the study of the early Universe, would remain at the state of the art for the next decades. Initially the ESA-led XEUS mission was proposed, with an effective area of several m2 and an angular resolution better than 2 arcsec HEW. Unfortunately, this mission was not implemented, mainly due to the costs and the low level of technology readiness. Currently the most advanced proposal for such a mission is the SMART-X project, led by CfA together with other US institutes. This project is based on adjustable segments of thin foil mirrors with piezo-electric actuators, aiming to achieve an effective area >2 m2 at 1 keV and an angular resolution better than 1 arcsec HEW. Another attractive technology to realize an X-ray telescope with similar characteristics is being developed at NASA/Goddard. In this case the mirrors are based on Si substrates that are super-polished and figured starting from a bulky Si ingot, from which they are properly cut. Here we propose an alternative method based on precise direct grinding, figuring and polishing of thin (a few mm) glass shells with innovative deterministic polishing methods. This is followed by a final correction via ion figuring to obtain the desired accuracy. For this purpose, a temporary stiffening structure is used to support the shell from the polishing operations up to its integration in the telescope supporting structure. This paper deals with the technological process under development, the results achieved so far and some mission scenarios based on this kind of optics, aiming to achieve an effective area more than 10 times larger than Chandra and an angular resolution of 1 arcsec HEW on axis and of a few arcsec off-axis across a large

  12. Solar activity: The Sun as an X-ray star

    NASA Technical Reports Server (NTRS)

    Golub, L.

    1981-01-01

    The existence and constant activity of the Sun's outer atmosphere are thought to be due to the continual emergence of magnetic fields from the Solar interior and the stressing of these fields at or near the surface layers of the Sun. The structure and activity of the corona are thus symptomatic of the underlying magnetic dynamo and the existence of an outer turbulent convective zone on the Sun. A sufficient condition for the existence of coronal activity on other stars would be the existence of a magnetic dynamo and an outer convective zone. The theoretical relationship between magnetic fields and coronal activity can be tested by Solar observations, for which the individual loop structures can be resolved. A number of parameters however, which enter into the alternative theoretical formulations remain fixed in all Solar observations. To determine whether these are truly parameters of the theory observations need to be extended to nearby stars on which suitable conditions may occur.

  13. High Energy Replicated Optics to Explore the Sun: Hard X-Ray Balloon-Borne Telescope

    NASA Technical Reports Server (NTRS)

    Gaskin, Jessica; Apple, Jeff; StevensonChavis, Katherine; Dietz, Kurt; Holt, Marlon; Koehler, Heather; Lis, Tomasz; O'Connor, Brian; RodriquezOtero, Miguel; Pryor, Jonathan; Ramsey, Brian; Rinehart-Dawson, Maegan; Smith, Leigh; Sobey, Alexander; Wilson-Hodge, Colleen; Christe, Steven; Cramer, Alexander; Edgerton, Melissa; Rodriquez, Marcello; Shih, Albert; Gregory, Don; Jasper, John; Bohon, Steven

    2013-01-01

    Set to fly in the Fall of 2013 from Ft. Sumner, NM, the High Energy Replicated Optics to Explore the Sun (HEROES) mission is a collaborative effort between the NASA Marshall Space Flight Center and the Goddard Space Flight Center to upgrade an existing payload, the High Energy Replicated Optics (HERO) balloon-borne telescope, to make unique scientific measurements of the Sun and astrophysical targets during the same flight. The HEROES science payload consists of 8 mirror modules, housing a total of 109 grazing-incidence optics. These modules are mounted on a carbon-fiber - and Aluminum optical bench 6 m from a matching array of high pressure xenon gas scintillation proportional counters, which serve as the focal-plane detectors. The HERO gondola utilizes a differential GPS system (backed by a magnetometer) for coarse pointing in the azimuth and a shaft angle encoder plus inclinometer provides the coarse elevation. The HEROES payload will incorporate a new solar aspect system to supplement the existing star camera, for fine pointing during both the day and night. A mechanical shutter will be added to the star camera to protect it during solar observations. HEROES will also implement two novel alignment monitoring system that will measure the alignment between the optical bench and the star camera and between the optics and detectors for improved pointing and post-flight data reconstruction. The overall payload will also be discussed. This mission is funded by the NASA HOPE (Hands On Project Experience) Training Opportunity awarded by the NASA Academy of Program/Project and Engineering Leadership, in partnership with NASA's Science Mission Directorate, Office of the Chief Engineer and Office of the Chief Technologist

  14. High Energy Replicated Optics to Explore the Sun: Hard X-ray balloon-borne telescope

    NASA Astrophysics Data System (ADS)

    Gaskin, J.; Apple, J.; Chavis, K. S.; Dietz, K.; Holt, M.; Koehler, H.; Lis, T.; O'Connor, B.; Otero, M. R.; Pryor, J.; Ramsey, B.; Rinehart-Dawson, M.; Smith, L.; Sobey, A.; Wilson-Hodge, C.; Christe, S.; Cramer, A.; Edgerton, M.; Rodriguez, M.; Shih, A.; Gregory, D.; Jasper, J.; Bohon, S.

    Set to fly in the Fall of 2013 from Ft. Sumner, NM, the High Energy Replicated Optics to Explore the Sun (HEROES) mission is a collaborative effort between the NASA Marshall Space Flight Center and the Goddard Space Flight Center to upgrade an existing payload, the High Energy Replicated Optics (HERO) balloon-borne telescope, to make unique scientific measurements of the Sun and astrophysical targets during the same flight. The HEROES science payload consists of 8 mirror modules, housing a total of 109 grazing-incidence optics. These modules are mounted on a carbon-fiber - and Aluminum optical bench 6 m from a matching array of high pressure xenon gas scintillation proportional counters, which serve as the focal-plane detectors. The HERO gondola utilizes a differential GPS system (backed by a magnetometer) for coarse pointing in the azimuth and a shaft angle encoder plus inclinometer provides the coarse elevation. The HEROES payload will incorporate a new solar aspect system to supplement the existing star camera, for fine pointing during both the day and night. A mechanical shutter will be added to the star camera to protect it during solar observations. HEROES will also implement two novel alignment monitoring system that will measure the alignment between the optical bench and the star camera and between the optics and detectors for improved pointing and post-flight data reconstruction. The overall payload will also be discussed. This mission is funded by the NASA HOPE (Hands On Project Experience) Training Opportunity awarded by the NASA Academy of Program/Project and Engineering Leadership, in partnership with NASA's Science Mission Directorate, Office of the Chief Engineer and Office of the Chief Technologist.

  15. Novel applications of diagnostic x-rays in activating photo-agents through x-ray induced visible luminescence from rare-earth particles: an in vitro study

    NASA Astrophysics Data System (ADS)

    Abliz, Erkinay; Collins, Joshua E.; Friedberg, Joseph S.; Kumar, Ajith; Bell, Howard; Waynant, Ronald W.; Tata, Darrell B.

    2010-02-01

    Photodynamic agents such as Photofrin II (Photo II) utilized in photodynamic therapy (PDT) possess a remarkable property to become preferentially retained within the tumor's micro-environment. Upon the photo-agent's activation through visible light photon absorption, the agents exert their cellular cytotoxicity through type II and type I mechanistic pathways through extensive generation of reactive oxygen species (ROS): singlet oxygen 1O2, superoxide anion O2 -, and hydrogen peroxide H2O2, within the intratumoral environment. Unfortunately, due to shallow visible light penetration depth (~2mm to 5mm) in tissues, the PDT strategy currently has largely been restricted to the treatments of surface tumors, such as the melanomas. Additional invasive strategies through optical fibers are currently utilized in getting the visible light into the intended deep seated targets within the body for PDT. In this communication, we report on a novel strategy in utilizing "soft" energy diagnostic X-rays to indirectly activate Photo II through X-ray induced luminescence from Gadolinium oxysulfide (20 micron dimension) particles doped with Terbium: Gd2O2S:Tb. X-ray induced visible luminescence from Gd2O2S:Tb particles was spectroscopically characterized and the ROS production levels from clinically relevant concentration (10 μg/ml) of Photo II was quantified through changes in the Vitamin C absorbance. ROS kinetics through X-ray induced luminescence was found to be similar to the ROS kinetics from red He-Ne laser exposures used in the clinics. Taken together, in-vitro findings herein provide the basis for future studies in determining the safety and efficacy of this non-invasive X-ray induced luminescence strategy in activating photo-agent in deep seated tumors.

  16. X-RAY FLUORESCENCE ANALYSIS OF HANFORD LOW ACTIVITY WASTE SIMULANTS METHOD DEVELOPMENT

    SciTech Connect

    Jurgensen, A; David Missimer, D; Ronny Rutherford, R

    2007-08-08

    The x-ray fluorescence laboratory (XRF) in the Analytical Development Directorate (ADD) of the Savannah River National Laboratory (SRNL) was requested to develop an x-ray fluorescence spectrometry method for elemental characterization of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) pretreated low activity waste (LAW) stream to the LAW Vitrification Plant. The WTP is evaluating the potential for using XRF as a rapid turnaround technique to support LAW product compliance and glass former batching. The overall objective of this task was to develop an XRF analytical method that provides rapid turnaround time (<8 hours), while providing sufficient accuracy and precision to determine variations in waste.

  17. No radio pulsations detected from SGR 1627-41 following renewed X- ray activity

    NASA Astrophysics Data System (ADS)

    Camilo, F.; Sarkissian, J.

    2008-06-01

    Starting on May 28, 2008, the SGR 1627-41 displayed X-ray bursting and enhanced flux after nearly 10 years of relative inactivity (ATEL #1548, #1549, #1555). Two magnetars are known to emit radio pulses (Camilo et al. 2007, ApJ, 666, L93), and in at least one case these are transient and have followed an X-ray outburst after many years in quiescence (Camilo et al. 2006, Nature, 442, 892). Therefore, although previous radio searches of SGR 1627-41 have been unsuccessful, we are searching for radio emission following its recent renewed burst of activity.

  18. On the origin of power-law X-ray spectra of active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Schlosman, I.; Shaham, J.; Shaviv, G.

    1984-01-01

    In the present analytical model for a power law X-ray continuum production in active galactic nuclei, the dissipation of turbulent energy flux above the accretion disk forms an optically thin transition layer with an inverted temperature gradient. The emitted thermal radiation has a power law spectrum in the 0.1-100 keV range, with a photon energy spectral index gamma of about 0.4-1.0. Thermal X-ray contribution from the layer is 5-10 percent of the total disk luminosity. The gamma value of 0.75 is suggested as a 'natural' power law index for Seyfert galaxies and QSOs.

  19. Solar x ray astronomy rocket program

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The dynamics were studied of the solar corona through the imaging of large scale coronal structures with AS&E High Resolution Soft X ray Imaging Solar Sounding Rocket Payload. The proposal for this program outlined a plan of research based on the construction of a high sensitivity X ray telescope from the optical and electronic components of the previous flight of this payload (36.038CS). Specifically, the X ray sensitive CCD camera was to be placed in the prime focus of the grazing incidence X ray mirror. The improved quantum efficiency of the CCD detector (over the film which had previously been used) allows quantitative measurements of temperature and emission measure in regions of low x ray emission such as helmet streamers beyond 1.2 solar radii or coronal holes. Furthermore, the improved sensitivity of the CCD allows short exposures of bright objects to study unexplored temporal regimes of active region loop evolution.

  20. Elliptically Bent X-ray Mirrors with Active Temperature Stabilization

    SciTech Connect

    Yuan, Sheng; Church, Matthew; Yashchuk, Valeriy V.; Goldberg, Kenneth A.; Celestre, Rich; McKinney, Wayne R.; Kirschman, Jonathan; Morrison, Greg; Noll, Tino; Warwick, Tony; Padmore, Howard A.

    2010-01-31

    We present details of design of elliptically bent Kirkpatrick-Baez mirrors developed and successfully used at the Advanced Light Source for submicron focusing. A distinctive feature of the mirror design is an active temperature stabilization based on a Peltier element attached directly to the mirror body. The design and materials have been carefully optimized to provide high heat conductance between the mirror body and substrate. We describe the experimental procedures used when assembling and precisely shaping the mirrors, with special attention paid to laboratory testing of the mirror-temperature stabilization. For this purpose, the temperature dependence of the surface slope profile of a specially fabricated test mirror placed inside a temperature-controlled container was measured. We demonstrate that with active mirror-temperature stabilization, a change of the surrounding temperature by more than 3K does not noticeably affect the mirror figure. Without temperature stabilization, the surface slope changes by approximately 1.5 ?mu rad rms (primarily defocus) under the same conditions.

  1. X-ray and Optical follow-up of the mid-2014 Outburst of Aql X-1 at peak and at low activity

    NASA Astrophysics Data System (ADS)

    Gandhi, Poshak; Dhillon, Vik S.; Tomsick, John A.; Butterley, Tim; Littlefair, Stuart M.; Wilson, Richard W.; Kennea, Jamie A.

    2014-09-01

    Following reports of optical and X-ray brightening of the soft X-ray transient Aql X-1 (ATel #6280, #6286), we obtained monitoring observations of the source with the Swift X-ray mission, and with the 0.5 m Durham/Sheffield robotic optical telescope located on La Palma.

  2. Production of thin glass mirrors by hot slumping for x-ray telescopes: present process and ongoing development

    NASA Astrophysics Data System (ADS)

    Salmaso, B.; Basso, S.; Brizzolari, C.; Civitani, M.; Ghigo, M.; Pareschi, G.; Spiga, D.; Tagliaferri, G.; Vecchi, G.

    2014-07-01

    Thin glass foils are considered good candidates to build a segmented X-ray telescope with effective area as large as 2 m2 and angular resolution better than 5 arcsec. In order to produce thin glass mirror segments, we developed a direct hot slumping technique assisted by pressure, in which the shape of a mould is replicated onto the optical surface of the glass. In this paper we present the result obtained with AF32 (by Schott) and EAGLE XG (by Corning) glass types. The selected mould material is Zerodur K20, as it does not require any anti-sticking layer and has a good matching, in terms of Coefficient of Thermal Expansion, with both glass types. Our group already produced a few prototypes, reaching angular resolution near 20 arcsec. In this work, relevant steps forward aimed at attaining a 5 arcsec angular resolution are described, along with the tuning of few key parameters in the slumping process. The results obtained on a newly procured cylindrical Zerodur K20 mould are presented.

  3. The thermal control system of the x-ray telescope eROSITA on Spektrum-Roentgen-Gamma

    NASA Astrophysics Data System (ADS)

    Fürmetz, Maria; Eder, Josef; Pfeffermann, Elmar; Predehl, Peter; Tiedemann, Lars

    2012-09-01

    The X-ray telescope eROSITA is the main instrument besides the Russian ART-XC on the Spektrum-Rontgen-Gamma mission. Starting from 2014, an all-sky survey will be performed in the range between 0.3-10keV, followed by pointed observations. The main objective of thismission is the detection of 100 0000 galaxy clusters in order to constrain cosmological parameters, amongst others the density distribution and evolution of dark energy. Due to the minimum lifetime of seven years the thermal control system has to be completely passive without any consumables. With the ideal operational temperature of the CCD cameras being between 173K and 183K, this requires a very effective heat rejection system, consisting of a complex heat pipe system and a good thermal insulation. Simultaneously, a very sensitive temperature control via variable conductance heat pipes is implemented. For special outgassing requirements at the betinning of the mission these heat pipes are not working after launch but can be switched on any time. On the other hand the mirror moduules have to be tempered at room temperature and more than 200W of the electronics have to be dissipated without affecting the surrounding components or the satellite structure. The thermal control system has to be able to keep up the required temperature range and has to guarantee the optimum working conditions for all parts of the instrument. Calculations and verification tests validated the thermal concept.

  4. Solar Observations during Skylab, April 1973-February 1974. I. Coronal X-Ray Structure. II. Solar Flare Activity,

    DTIC Science & Technology

    1983-02-01

    Telephone: (704) 258-25501 World Dats Center A for Solor -Terrestrial Physics Geigrphy.Navironmmtel Data and Information Service, MOMA World Data...association of a solar wind stream with a coronal hole photographed on a rocket flight in 1970 (1.iager et at., 1973]. Later, the ASE Skylab data from the S...054 X-ray spectrographic telescope allowed us to extend the associations between coronal X-ray structure and solar wind streams [Krieage et at., 1976

  5. Anticorrelation of Variability Amplitude with X-Ray Luminosity for Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Bao, Gang; Abramowicz, Marek A.

    1996-07-01

    The bright-spot model for the short-term X-ray variability of active galactic nuclei predicts that, statistically, sources with larger luminosities should have smaller variability amplitudes. This quantitatively agrees with the analysis of the observational data from 12 high-quality EXOSAT long looks performed by Lawrence & Papadakis.

  6. Principles, Practical Problems, and the Performance of MEM Imaging for the YOHKOH Hard X-ray Telescope

    NASA Astrophysics Data System (ADS)

    Kosugi, Takeo; Sato, Jun; Sakao, Taro; Masuda, Satoshi

    1997-05-01

    The Hard X-ray Telescope (HXT) on-board Yohkoh is a Fourier-synthesis telescope with 64 modulation collimators. Solar flare images have been synthesized using the Maximum Entropy Method (MEM) or some other imaging techniques from sets of the 64 photon counts. This paper reports our recent success in improving the MEM imaging for HXT. The key factors that led us to this success are as follows. First, modulation patterns for the 64 individual collimators were precisely re-calibrated in orbit using solar flares themselves as calibration sources. Note that the patterns we had used before were based on the pre-launch calibrations using artificial sources. Also the formulae that represent the patterns are renewed. Second, we re-formulated the MEM principle; now the total flux is a free parameter to be determined by the MEM principle. This new formulation was successfully incorporated into an iterative code. Third, the observation error terms were estimated and incorporated properly in the MEM imaging. With these improvements, we have confirmed (i) that the so-called over-resolution problem, sometimes misunderstood as resulting from the MEM principle itself, disappears so that the stability of images improves drastically, (ii) that the image quality improves proportionally with increasing photon counts as naturally expected, (iii) that the number of events for which MEM imaging fails decreases (with a small number of exceptions, maybe due to large intrinsic source size), and (iv) that the similarity between HXT L-band images and SXT images becomes much clearer than before.

  7. A normal incidence high resolution X-ray telescope for solar coronal observations

    NASA Technical Reports Server (NTRS)

    Golub, Leon

    1987-01-01

    The preflight preparation of the multilayer mirror fabrication and testing, integration and testing, and WSMR activities are described. Post-flight analysis shows that all payload systems and subsystems performed well within acceptable limits, with the sole exception of the light-blocking prefilters. Suggested corrective actions were discussed. Refurbishment and reflight are then described.

  8. Active Galactic Nuclei, Quasars, BL Lac Objects and X-Ray Background

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard (Technical Monitor); Elvis, Martin

    2005-01-01

    The XMM COSMOS survey is producing the large surface density of X-ray sources anticipated. The first batch of approx. 200 sources is being studied in relation to the large scale structure derived from deep optical/near-IR imaging from Subaru and CFHT. The photometric redshifts from the opt/IR imaging program allow a first look at structure vs. redshift, identifying high z clusters. A consortium of SAO, U. Arizona and the Carnegie Institute of Washington (Pasadena) has started a large program using the 6.5meter Magellan telescopes in Chile with the prime objective of identifying the XMM X-ray sources in the COSMOS field. The first series of observing runs using the new IMACS multi-slit spectrograph on Magellan will take place in January and February of 2005. Some 300 spectra per field will be taken, including 70%-80% of the XMM sources in each field. The four first fields cover the center of the COSMOS field. A VLT consortium is set to obtain bulk redshifts of the field galaxies. The added accuracy of the spectroscopic redshifts over the photo-z's will allow much lower density structures to be seen, voids and filaments. The association of X-ray selected AGNs, and quasars with these filaments, is a major motivation for our studies. Comparison to the deep VLA radio data now becoming available is about to begin.

  9. The Discovery of X-ray Emission from Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Elvis, Martin

    2013-01-01

    Back in 1974 the UHURU catalog (3U) had been published with many UHGLS - unidentified high galactic latitude sources. Identifications were hampered by the square degree sized error boxes (positional uncertainties). Could these explain the cosmic X-ray background? Could UHGLS be "X-ray galaxies"? Only three active galaxies (AGNs) had been found as X-ray sources: 3C273, Cen A and NGC 4151, while others had upper limits. What was the difference between X-ray and non-X-ray AGNs? It turned out that the slightly better positioning capability and slightly deeper sensitivity of the Ariel V Sky Survey Instrument (SSI), launched in October 1974, were just enough to show that the UHGLS were Seyfert galaxies. And I was lucky enough that I'd joined the Leicester X-ray group and had taken on the UHGLS for my PhD thesis, with Ken Pounds as my supervisor. With the SSI we made a catalog of high latitude sources, the "2A" catalog, including about a dozen known Seyfert galaxies (lowish luminosity nearby AGNs) and, with Mike Penston and Martin Ward, we went on to identify many of them with both newly discovered normal broad emission line AGNs and a few new "narrow emission line galaxies", or NELGs, as we called them. We are now convinced that it is summation of many obscured NELGs that produce the flat spectrum of the X-ray background, and we are still searching for them in Chandra deep surveys and at higher energies with NuSTAR. There was an obvious connection between the X-ray obscuration and the optical reddening, which must lie outside the region emitting the broad optical spectral lines. Andy Lawrence and I, following a clue from Bill Keel, put this together into what we now call the Unified Scheme for AGN structure. This idea of a flattened torus obscuring the inner regions of the AGN was so dramatically confirmed a few years later -- by Ski Antonucci and Joe Miller's discovery of polarized broad emission lines in NGC1068 -- that the precursor papers became irrelevant. But Ariel

  10. Technology Requirements For a Square-Meter, Arcsecond-Resolution Telescope for X-Rays: The SMART-X Mission

    NASA Technical Reports Server (NTRS)

    Schwartz, Daniel A.; Allured, Ryan; Bookbinder, Jay; Cotroneo, Vincenzo; Forman, William; Freeman, Mark; McMuldroch, Stuart; Reid, Paul; Tananbaum, Harvey; Vikhlinin, Alexey; Johnson-Wilke, Raegan; Trolier-McKinstry, Susan; Wilke, Rudeger; Gubarev, Mikhail; Kolodziejczak, Jeffrey; O'Dell, Steve; Ramsey, Brian

    2014-01-01

    Addressing the astrophysical problems of the 2020's requires sub-arcsecond x-ray imaging with square meter effective area. Such requirements can be derived, for example, by considering deep x-ray surveys to find the young black holes in the early universe (large redshifts) which will grow into the first supermassive black holes. We have envisioned a mission based on adjustable x-ray optics technology, in order to achieve the required reduction of mass to collecting area for the mirrors. We are pursuing technology which effects this adjustment via thin film piezoelectric "cells" deposited directly on the non-reflecting sides of thin, slumped glass. While SMARTX will also incorporate state-of-the-art x-ray cameras, the remaining spacecraft systems have no more stringent requirements than those which are well understood and proven on the current Chandra X-ray Observatory.

  11. Swift X-Ray Telescope Observations of the Nova-like Cataclysmic Variables MV Lyr, BZ Cam, and V592 Cas

    NASA Astrophysics Data System (ADS)

    Balman, Şölen; Godon, Patrick; Sion, Edward M.

    2014-10-01

    We present a total of ~45 ks (3 × 15 ks) of Swift X-Ray Telescope (XRT) observations for three nonmagnetic nova-like (NL) cataclysmic variables (CVs; MV Lyr, BZ Cam, V592 Cas) in order to study characteristics of boundary layers (BLs) in CVs. The nonmagnetic NLs are found mostly in a state of high mass accretion rate (>=1 × 10-9 M ⊙ yr-1), and some show occasional low states. Using the XRT data, we find optically thin multiple-temperature cooling flow type emission spectra with X-ray temperatures (kT max) of 21-50 keV. These hard X-ray-emitting BLs diverge from simple isobaric cooling flows, indicating X-ray temperatures that are of virial values in the disk. In addition, we detect power-law emission components from MV Lyr and BZ Cam and plausibly from V592 Cas, which may be a result of the Compton scattering of the optically thin emission from the fast wind outflows in these systems and/or Compton upscattering of the soft disk photons. The X-ray luminosities of the (multitemperature) thermal plasma emission in the 0.1-50.0 keV range are (0.9-5.0) × 1032 erg s-1. The ratio of the X-ray and disk luminosities (calculated from the UV-optical wavelengths) yields an efficiency (Lx /L disk) ~ 0.01-0.001. Given this non-radiative ratio for the X-ray-emitting BLs with no significant optically thick blackbody emission in the soft X-rays (consistent with ROSAT observations), together with the high/virial X-ray temperatures, we suggest that high-state NL systems may have optically thin BLs merged with ADAF-like flows and/or X-ray coronae. In addition, we note that the axisymmetric bipolar and/or rotation-dominated fast-wind outflows detected in these three NLs (particularly BZ Cam and V592 Cas) or some other NL may also be explained in the context of ADAF-like BL regions.

  12. Swift X-ray telescope observations of the nova-like cataclysmic variables MV Lyr, BZ Cam, and V592 Cas

    SciTech Connect

    Balman, Şölen; Godon, Patrick; Sion, Edward M. E-mail: patrick.godon@villanova.edu

    2014-10-10

    We present a total of ∼45 ks (3 × 15 ks) of Swift X-Ray Telescope (XRT) observations for three nonmagnetic nova-like (NL) cataclysmic variables (CVs; MV Lyr, BZ Cam, V592 Cas) in order to study characteristics of boundary layers (BLs) in CVs. The nonmagnetic NLs are found mostly in a state of high mass accretion rate (≥1 × 10{sup –9} M {sub ☉} yr{sup –1}), and some show occasional low states. Using the XRT data, we find optically thin multiple-temperature cooling flow type emission spectra with X-ray temperatures (kT {sub max}) of 21-50 keV. These hard X-ray-emitting BLs diverge from simple isobaric cooling flows, indicating X-ray temperatures that are of virial values in the disk. In addition, we detect power-law emission components from MV Lyr and BZ Cam and plausibly from V592 Cas, which may be a result of the Compton scattering of the optically thin emission from the fast wind outflows in these systems and/or Compton upscattering of the soft disk photons. The X-ray luminosities of the (multitemperature) thermal plasma emission in the 0.1-50.0 keV range are (0.9-5.0) × 10{sup 32} erg s{sup –1}. The ratio of the X-ray and disk luminosities (calculated from the UV-optical wavelengths) yields an efficiency (L{sub x} /L {sub disk}) ∼ 0.01-0.001. Given this non-radiative ratio for the X-ray-emitting BLs with no significant optically thick blackbody emission in the soft X-rays (consistent with ROSAT observations), together with the high/virial X-ray temperatures, we suggest that high-state NL systems may have optically thin BLs merged with ADAF-like flows and/or X-ray coronae. In addition, we note that the axisymmetric bipolar and/or rotation-dominated fast-wind outflows detected in these three NLs (particularly BZ Cam and V592 Cas) or some other NL may also be explained in the context of ADAF-like BL regions.

  13. Beyond Chandra (towards the X-ray Surveyor mission): possible solutions for the implementation of very high angular resolution X-ray telescopes in the new millennium based on fused silica segments

    NASA Astrophysics Data System (ADS)

    Pareschi, G.; Basso, S.; Civitani, M. M.; Ghigo, M.; Parodi, G.; Pelliciari, C.; Salmaso, B.; Spiga, D.; Vecchi, G.

    2016-07-01

    An important challenge for the X-ray astronomy of the new millennium is represented by the implementation of an Xray telescope able to maintain the exquisite angular resolution of Chandra (with a sub-arcsec HEW, on-axis) but, at the same time, being characterized by a much larger throughput and grasp. A mission with similar characteristics is represented by the X-ray Surveyor Mission. The project has been recently proposed in USA and is being currently studied by NASA. It will host an X-ray telescope with an effective area of more than 2 square meters at 1 keV (i.e. 30 times greater than Chandra) and a 15-arcminutes field-of-view, with 1-arcsecond or better half-power diameter (versus the 4 arcmin diameter of Chandra). While the scientific reasons for implementing a similar mission are clear, being related to compelling problems like e.g. the formation and subsequent growth of black hole seeds at very high redshift or the identification of the first galaxy groups and proto-clusters, the realization of a grazing-angle optics system able to fulfil these specs remain highly challenging. Different technologies are being envisaged, like e.g. the use of adjustable segmented mirrors (with use of piezoelectric or magneto-restrictive film actuators on the back surface) or the direct polishing of a variety of thin substrates or the use of innovative correction methods like e.g. differential deposition, ionfiguring or the correction of the profile via controlled stress films. In this paper we present a possible approach based on the direct polishing (with final ion figuring correction of the profile) of thin SiO2 segmented substrates (typically 2 mm thick), discussing different aspects of the technology under implementation and presenting some preliminary results.

  14. Constraining black hole masses in low-accreting active galactic nuclei using X-ray spectra

    NASA Astrophysics Data System (ADS)

    Jang, I.; Gliozzi, M.; Hughes, C.; Titarchuk, L.

    2014-09-01

    In a recent work we demonstrated that a novel X-ray scaling method, originally introduced for Galactic black holes (BHs), can be reliably extended to estimate the mass of supermassive BHs accreting at a moderate to high level. Here we investigate the limits of applicability of this method to low-accreting active galactic nuclei (AGN), using a control sample with good-quality X-ray data and dynamically measured mass. For low-accreting AGN (LX/LEdd ≤ 10-4), because the basic assumption that the photon index positively correlates with the accretion rate no longer holds the X-ray scaling method cannot be used. Nevertheless, the inverse correlation in the Γ-LX/LEdd diagram, found in several low-accreting BHs and confirmed by this sample, can be used to constrain MBH within a factor of ˜10 from the dynamically determined values. We provide a simple recipe to determine MBH using solely X-ray spectral data, which can be used as a sanity check for MBH determination based on indirect optical methods.

  15. Hyper X-ray Flares on Active Stars Detected with MAXI

    NASA Astrophysics Data System (ADS)

    Higa, Masaya; Tsuboi, Yohko; Negoro, Hitoshi; Nakahira, Satoshi; Tomida, Hiroshi; Matsuoka, Masaru; aff002

    2014-08-01

    MAXI started its operation in 2009 August. Owing to its unprecedentedly high sensitivity as an all-sky X-ray monitor and to its capability of real-time data transfer, we have detected 56 strong flares from twenty-one active stars (eleven RS CVn systems, one Algol system, seven dMe stars, one dKe star and one Young Stellar Object). These flares have large X-ray luminosity of 6 × 1030 -5 × 1033 ergs s-1 in the 2-20 keV band. The flares can be thought to be high ends among their own categories. During the flare from AT Mic on 2012 April 18th, one of the largest X-ray luminosities was recorded as a dMe star, 6 × 1032 ergs s-1 in the 2-20 keV band. It is larger than its bolometric luminosity by 4 times. The total energy emitted during the flare is 1036 ergs in the same band. Such total energy can be obtained on large flares from RS CVn system, but not on any other flares from dMe stars. In this proceeding, we report on the present situation in characteristics of hyper X-ray flares on each stellar categories.

  16. Future lunar mission Active X-ray Spectrometer development: Surface roughness and geometry studies

    NASA Astrophysics Data System (ADS)

    Naito, M.; Hasebe, N.; Kusano, H.; Nagaoka, H.; Kuwako, M.; Oyama, Y.; Shibamura, E.; Amano, Y.; Ohta, T.; Kim, K. J.; Lopes, J. A. M.

    2015-07-01

    The Active X-ray Spectrometer (AXS) is considered as one of the scientific payload candidates for a future Japanese mission, SELENE-2. The AXS consists of pyroelectric X-ray generators and a Silicon Drift Detector to conduct X-Ray Fluorescence spectroscopy (XRF) on the Moon to measure major elements: Mg, Al, Si, Ca, Ti, and Fe; minor elements: Na, K, P, S, Cr and Mn; and the trace element Ni depending on their concentration. Some factors such as roughness, grain size and porosity of sample, and the geometry of X-ray incidence, emission and energy will affect the XRF measurements precision. Basic studies on the XRF are required to develop the AXS. In this study, fused samples were used to make homogeneous samples free from the effect of grain size and porosity. Experimental and numerical studies on the XRF were conducted to evaluate the effects from incidence and emission angles and surface roughness. Angle geometry and surface roughness will be optimized for the design of the AXS on future missions from the results of the experiment and the numerical simulation.

  17. A Micromegas-based low-background x-ray detector coupled to a slumped-glass telescope for axion research

    SciTech Connect

    Aznar, F.; Castel, J.; Dafni, T. E-mail: jfcastel@unizar.es [Grupo de Física Nuclear y Astropartículas, Universidad de Zaragoza, C and others

    2015-12-01

    We report on the design, construction and operation of a low background x-ray detection line composed of a shielded Micromegas detector of the microbulk technology. The detector is made from radiopure materials and is placed at the focal point of a ∼ 5 cm diameter, 1.5 m focal-length, cone-approximation Wolter I x-ray telescope (XRT) assembled from thermally-formed (or 'slumped') glass substrates deposited with multilayer coatings. The system has been conceived as a technological pathfinder for the future International Axion Observatory (IAXO), as it combines two of the techniques (optic and detector) proposed in the conceptual design of the project. It is innovative for two reasons: it is the first time an x-ray optic has been designed and fabricated specifically for axion research, and the first time a Micromegas detector has been operated with an x-ray optic. The line has been installed at one end of the CERN Axion Solar Telescope (CAST) magnet and is currently looking for solar axions. The combination of the XRT and Micromegas detector provides the best signal-to-noise ratio obtained so far by any detection system of the CAST experiment with a background rate of 5.4×10{sup −3} counts per hour in the energy region-of-interest and signal spot area.

  18. Ionized Absorbers in Active Galactic Nuclei and Very Steap Soft X-Ray Quasars

    NASA Technical Reports Server (NTRS)

    Fiore, Fabrizio; White, Nicholas (Technical Monitor)

    2000-01-01

    Steep soft X-ray (0.1-2 keV) quasars share several unusual properties: narrow Balmer lines, strong Fe II emission, large and fast X-ray variability, and a rather steep 2-10 keV spectrum. These intriguing objects have been suggested to be the analogues of Galactic black hole candidates in the high, soft state. We present here results from ASCA observations for two of these quasars: NAB 0205 + 024 and PG 1244 + 026. Both objects show similar variations (factor of approximately 2 in 10 ks), despite a factor of approximately 10 difference in the 0.5-10 keV luminosity (7.3 x 10(exp 43) erg/s for PG 1244 + 026 and 6.4 x 10(exp 44) erg/s for NAB 0205 + 024, assuming isotropic emission, H(sub 0) = 50.0 and q(sub 0) = 0.0). The X-ray continuum of the two quasars flattens by 0.5-1 going from the 0.1-2 keV band towards higher energies, strengthening recent results on another half-dozen steep soft X-ray active galactic nuclei. PG 1244 + 026 shows a significant feature in the '1-keV' region, which can be described either as a broad emission line centered at 0.95 keV (quasar frame) or as edge or line absorption at 1.17 (1.22) keV. The line emission could be a result of reflection from a highly ionized accretion disc, in line with the view that steep soft X-ray quasars are emitting close to the Eddington luminosity. Photoelectric edge absorption or resonant line absorption could be produced by gas outflowing at a large velocity (0.3-0.6 c).

  19. Active Galaxy Unification in the Era of X-Ray Polarimetry

    NASA Technical Reports Server (NTRS)

    Dorodnitsyn, A.; Kallman, T.

    2010-01-01

    Active galactic nuclei (AGNs), Seyfert galaxies, and quasars are powered by luminous accretion and often accompanied by winds that are powerful enough to affect the AGN mass budget, and whose observational appearance bears an imprint of processes that are happening within the central parsec around the black hole (BH). One example of such a wind is the partially ionized gas responsible for X-ray and UV absorption (warm absorbers). Here, we show that such gas will have a distinct signature when viewed in polarized X-rays. Observations of such polarization can test models for the geometry of the flow and the gas responsible for launching and collimating it. We present calculations that show that the polarization depends on the hydrodynamics of the flow, the quantum mechanics of resonance-line scattering, and the transfer of polarized X-ray light in the highly ionized moving gas. The results emphasize the three-dimensional nature of the wind for modeling spectra. We show that the polarization in the 0.1-10 keV energy range is dominated by the effects of resonance lines. We predict a 5%-25% X-ray polarization signature of type-2 objects in this energy range. These results are generalized to flows that originate from a cold torus-like structure, located approximately 1 pc from the BH, which wraps the BH and is ultimately responsible for the apparent dichotomy between type 1 and type 2 AGNs. Such signals will be detectable by future dedicated X-ray polarimetry space missions, such as the NASA Gravity and Extreme Magnetism Small Explorer SMEX, "GEMS" Swank et al. (2008).

  20. ACTIVE GALAXY UNIFICATION IN THE ERA OF X-RAY POLARIMETRY

    SciTech Connect

    Dorodnitsyn, A.; Kallman, T.

    2010-03-10

    Active galactic nuclei (AGNs), Seyfert galaxies, and quasars are powered by luminous accretion and often accompanied by winds that are powerful enough to affect the AGN mass budget, and whose observational appearance bears an imprint of processes that are happening within the central parsec around the black hole (BH). One example of such a wind is the partially ionized gas responsible for X-ray and UV absorption (warm absorbers). Here, we show that such gas will have a distinct signature when viewed in polarized X-rays. Observations of such polarization can test models for the geometry of the flow and the gas responsible for launching and collimating it. We present calculations that show that the polarization depends on the hydrodynamics of the flow, the quantum mechanics of resonance-line scattering, and the transfer of polarized X-ray light in the highly ionized moving gas. The results emphasize the three-dimensional nature of the wind for modeling spectra. We show that the polarization in the 0.1-10 keV energy range is dominated by the effects of resonance lines. We predict a 5%-25% X-ray polarization signature of type-2 objects in this energy range. These results are generalized to flows that originate from a cold torus-like structure, located {approx}1 pc from the BH, which wraps the BH and is ultimately responsible for the apparent dichotomy between type 1 and type 2 AGNs. Such signals will be detectable by future dedicated X-ray polarimetry space missions, such as the NASA Gravity and Extreme Magnetism Small Explorer.

  1. A CANDIDATE ACTIVE GALACTIC NUCLEUS WITH A PURE SOFT THERMAL X-RAY SPECTRUM

    SciTech Connect

    Terashima, Yuichi; Kamizasa, Naoya; Awaki, Hisamitsu; Kubota, Aya; Ueda, Yoshihiro

    2012-06-20

    We report the discovery of a candidate active galactic nucleus (AGN), 2XMM J123103.2+110648 at z = 0.13, with an X-ray spectrum represented purely by soft thermal emission reminiscent of Galactic black hole (BH) binaries in the disk-dominated state. This object was found in the second XMM-Newton serendipitous source catalog as a highly variable X-ray source. In three separate observations, its X-ray spectrum can be represented either by a multicolor disk blackbody model with an inner temperature of kT{sub in} Almost-Equal-To 0.16-0.21 keV or a Wien spectrum Comptonized by an optically thick plasma with kT Almost-Equal-To 0.14-0.18 keV. The soft X-ray luminosity in the 0.5-2 keV band is estimated to be (1.6-3.8) Multiplication-Sign 10{sup 42} erg s{sup -1}. Hard emission above {approx}2 keV is not detected. The ratio of the soft to hard emission is the strongest among AGNs observed thus far. Spectra selected in high/low-flux time intervals are examined in order to study spectral variability. In the second observation with the highest signal-to-noise ratio, the low-energy (below 0.7 keV) spectral regime flattens when the flux is high, while the shape of the high-energy part (1-1.7 keV) remains unchanged. This behavior is qualitatively consistent with being caused by strong Comptonization. Both the strong soft excess and spectral change consistent with Comptonization in the X-ray spectrum imply that the Eddington ratio is large, which requires a small BH mass (smaller than {approx}10{sup 5} M{sub Sun }).

  2. X-ray imaging of chemically active valence electrons during a pericyclic reaction

    PubMed Central

    Bredtmann, Timm; Ivanov, Misha; Dixit, Gopal

    2014-01-01

    Time-resolved imaging of chemically active valence electron densities is a long-sought goal, as these electrons dictate the course of chemical reactions. However, X-ray scattering is always dominated by the core and inert valence electrons, making time-resolved X-ray imaging of chemically active valence electron densities extremely challenging. Here we demonstrate an effective and robust method, which emphasizes the information encoded in weakly scattered photons, to image chemically active valence electron densities. The degenerate Cope rearrangement of semibullvalene, a pericyclic reaction, is used as an example to visually illustrate our approach. Our work also provides experimental access to the long-standing problem of synchronous versus asynchronous bond formation and breaking during pericyclic reactions. PMID:25424639

  3. Soft X-ray variability over the present minimum of solar activity as observed by SphinX

    NASA Astrophysics Data System (ADS)

    Gburek, S.; Siarkowski, M.; Kepa, A.; Sylwester, J.; Kowalinski, M.; Bakala, J.; Podgorski, P.; Kordylewski, Z.; Plocieniak, S.; Sylwester, B.; Trzebinski, W.; Kuzin, S.

    2011-04-01

    Solar Photometer in X-rays (SphinX) is an instrument designed to observe the Sun in X-rays in the energy range 0.85-15.00 keV. SphinX is incorporated within the Russian TESIS X and EUV telescope complex aboard the CORONAS-Photon satellite which was launched on January 30, 2009 at 13:30 UT from the Plesetsk Cosmodrome, northern Russia. Since February, 2009 SphinX has been measuring solar X-ray radiation nearly continuously. The principle of SphinX operation and the content of the instrument data archives is studied. Issues related to dissemination of SphinX calibration, data, repository mirrors locations, types of data and metadata are discussed. Variability of soft X-ray solar flux is studied using data collected by SphinX over entire mission duration.

  4. X-ray excited ZnS:Cu,Co afterglow nanoparticles for photodynamic activation

    NASA Astrophysics Data System (ADS)

    Ma, Lun; Zou, Xiaoju; Bui, Brian; Chen, Wei; Song, Kwang Hyun; Solberg, Timothy

    2014-07-01

    Copper and cobalt co-doped ZnS (ZnS:Cu,Co) afterglow nanoparticles were conjugated to photosensitizer tetrabromorhodamine-123 (TBrRh123) and efficient energy transfer from the nanoparticles to TBrRh123 was observed. In addition to their X-ray excited luminescence, the ZnS:Cu,Co nanoparticles also show long lasting afterglow, which continuously serve as a light source for photodynamic therapy (PDT) activation. Compared to TBrRh123 or ZnS:Cu,Co alone, the ZnS:Cu,Co-TBrRh123 conjugates show low dark toxicity but high X-ray induced toxicity to human prostate cancer cells. The results indicate that the ZnS:Cu,Co afterglow nanoparticles have a good potential for PDT activation.

  5. SWIFT X-RAY TELESCOPE STUDY OF THE BLACK HOLE BINARY MAXI J1659–152: VARIABILITY FROM A TWO COMPONENT ACCRETION FLOW

    SciTech Connect

    Kalamkar, M.; Klis, M. van der; Heil, L.; Homan, J.

    2015-08-01

    We present an energy dependent X-ray variability study of the 2010 outburst of the black hole X-ray binary MAXI J1659–152 with the Swift X-ray Telescope (XRT). The broadband noise components and the quasi-periodic oscillations (QPO) observed in the power spectra show a strong and varied energy dependence. Combining Swift XRT data with data from the Rossi X-ray Timing Explorer, we report, for the first time, an rms spectrum (fractional rms amplitude as a function of energy) of these components in the 0.5–30 keV energy range. We find that the strength of the low-frequency component (<0.1 Hz) decreases with energy, contrary to the higher frequency components (>0.1 Hz) whose strengths increase with energy. In the context of the propagating fluctuations model for X-ray variability, we suggest that the low-frequency component originates in the accretion disk (which dominates emission below ∼2 keV) and the higher frequency components are formed in the hot flow (which dominates emission above ∼2 keV). As the properties of the QPO suggest that it may have a different driving mechanism, we investigate the Lense–Thirring precession of the hot flow as a candidate model. We also report on the QPO coherence evolution for the first time in the energy band below 2 keV. While there are strong indications that the QPO is less coherent at energies below 2 keV than above 2 keV, the coherence increases with intensity similar to what is observed at energies above 2 keV in other black hole X-ray binaries.

  6. An X-Ray Photoelectron Spectroscopy (XPS) Study of Activated Carbons Impregnated with some Organocopper Complexes,

    DTIC Science & Technology

    1993-10-01

    AD-A282 721 l lllllll a Dfene Defence nationals AN X.RAY PHOTOELECTRON SPECTROSCOPY (XPS) STUDY OF ACTIVATED CARBONS IMPREGNATED WITH SOME... ammoniacal solution as a carrier into which all impregnants (except TEDA) were dissolved. Without a suitable carrier, and with the inherent low vapor...and will not be repeated here. All five complexes were synthesized at DREO using known methods. 2 2.2 IMPREGNATING PROCEDURES Two impregnating

  7. Image Properties of an X-Ray Telescope of the Wolter-1 Type with Emphasis on Contrast Reduction by Diffuse Reflection. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Lenzen, R.

    1980-01-01

    Theoretical and experimental results are presented on the geometrical-optic imaging properties of a Wolter-1 type paraboloid-hyperboloid X-ray telescope. Particular consideration is given to the effect of microroughness of the mirror on the imaging properties. Experiments were conducted in which scattering properties were determined as a function of wavelength, incidence angle, and roughness of the plane mirrors. Results indicate the need for optimization of mirror material and polishing technology as well as the development of improved mirror manufacturing techniques. The use of transmission gratings along with the Wolter-1 type telescope in spectroscopy applications is discussed.

  8. X-ray imaging characterization of active edge silicon pixel sensors

    NASA Astrophysics Data System (ADS)

    Ponchut, C.; Ruat, M.; Kalliopuska, J.

    2014-05-01

    The aim of this work was the experimental characterization of edge effects in active-edge silicon pixel sensors, in the frame of X-ray pixel detectors developments for synchrotron experiments. We produced a set of active edge pixel sensors with 300 to 500 μm thickness, edge widths ranging from 100 μm to 150 μm, and n or p pixel contact types. The sensors with 256 × 256 pixels and 55 × 55 μm2 pixel pitch were then bump-bonded to Timepix readout chips for X-ray imaging measurements. The reduced edge widths makes the edge pixels more sensitive to the electrical field distribution at the sensor boundaries. We characterized this effect by mapping the spatial response of the sensor edges with a finely focused X-ray synchrotron beam. One of the samples showed a distortion-free response on all four edges, whereas others showed variable degrees of distortions extending at maximum to 300 micron from the sensor edge. An application of active edge pixel sensors to coherent diffraction imaging with synchrotron beams is described.

  9. Piecing together the X-ray background: bolometric corrections for active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Vasudevan, R. V.; Fabian, A. C.

    2007-11-01

    The X-ray background can be used to constrain the accretion history of supermassive black holes (SMBHs) in active galactic nuclei (AGN), with the SMBH mass density related to the energy density due to accretion. A knowledge of the hard X-ray bolometric correction, κ2-10keV, is a vital input into these studies, as it allows us to constrain the parameters of the accretion responsible for SMBH growth. Earlier studies assumed a constant bolometric correction for all AGN, and more recent work has suggested accounting for a dependence on AGN luminosity. Until recently, the variations in the disc emission in the ultraviolet (UV) have not been taken into account in this calculation; we show that such variations are important by construction of optical-to-X-ray spectral energy distributions for 54 AGN. In particular, we use Far Ultraviolet Spectroscopic Explorer (FUSE) UV and X-ray data from the literature to constrain the disc emission as well as possible. We find evidence for very significant spread in the bolometric corrections, with no simple dependence on luminosity being evident. Populations of AGN such as narrow-line Seyfert 1 nuclei, radio-loud and X-ray-weak AGN may have bolometric corrections which differ systematically from the rest of the AGN population. We identify other sources of uncertainty including intrinsic extinction in the optical-UV, X-ray and UV variability and uncertainties in SMBH mass estimates. Our results suggest a more well-defined relationship between the bolometric correction and Eddington ratio in AGN, with a transitional region at an Eddington ratio of ~0.1, below which the bolometric correction is typically 15-25, and above which it is typically 40-70. We consider the potential-implied parallels with the low/hard and high/soft states in Galactic black hole (GBH) accretion, and present bolometric corrections for the GBH binary GX 339-4 for comparison. Our findings reinforce previous studies proposing a multistate description of AGN

  10. Ensemble X-ray variability of active galactic nuclei. II. Excess variance and updated structure function

    NASA Astrophysics Data System (ADS)

    Vagnetti, F.; Middei, R.; Antonucci, M.; Paolillo, M.; Serafinelli, R.

    2016-09-01

    Context. Most investigations of the X-ray variability of active galactic nuclei (AGN) have been concentrated on the detailed analyses of individual, nearby sources. A relatively small number of studies have treated the ensemble behaviour of the more general AGN population in wider regions of the luminosity-redshift plane. Aims: We want to determine the ensemble variability properties of a rich AGN sample, called Multi-Epoch XMM Serendipitous AGN Sample (MEXSAS), extracted from the fifth release of the XMM-Newton Serendipitous Source Catalogue (XMMSSC-DR5), with redshift between ~0.1 and ~5, and X-ray luminosities in the 0.5-4.5 keV band between ~1042 erg/s and ~1047 erg/s. Methods: We urge caution on the use of the normalised excess variance (NXS), noting that it may lead to underestimate variability if used improperly. We use the structure function (SF), updating our previous analysis for a smaller sample. We propose a correction to the NXS variability estimator, taking account of the light curve duration in the rest frame on the basis of the knowledge of the variability behaviour gained by SF studies. Results: We find an ensemble increase of the X-ray variability with the rest-frame time lag τ, given by SF ∝ τ0.12. We confirm an inverse dependence on the X-ray luminosity, approximately as SF ∝ LX-0.19. We analyse the SF in different X-ray bands, finding a dependence of the variability on the frequency as SF ∝ ν-0.15, corresponding to a so-called softer when brighter trend. In turn, this dependence allows us to parametrically correct the variability estimated in observer-frame bands to that in the rest frame, resulting in a moderate (≲15%) shift upwards (V-correction). Conclusions: Ensemble X-ray variability of AGNs is best described by the structure function. An improper use of the normalised excess variance may lead to an underestimate of the intrinsic variability, so that appropriate corrections to the data or the models must be applied to prevent

  11. Investigation of X-ray and optical solar flare activities during solar cycles 22 and 23

    NASA Astrophysics Data System (ADS)

    Akimov, L. A.; Belkina, I. L.; Bushueva, T. P.

    2003-02-01

    Daily X-ray flare indices (XFI) for the interval from January 1986 till June 2002 were calculated. The XFI behaviour during solar cycles 22 and 23 was studied. We compare the daily XFI with the daily optical flare indices (OFI) and with the International Relative Sunspot Numbers. The energy emitted by X-ray flares during 77 months of solar cycle 22 is shown to be about five times larger than the analogous value for the present solar cycle. We revealed statistically significant maxima in power spectra of the XFI and OFI. They correspond to periods of 25.5, 36.5, 73, 116, and 150d which presumably are appropriate to characteristic frequencies of the solar flare activity. A hypothesis on an possible effect of Mercury's variable electric charge on the origin of solar flares is proposed and corresponding estimates were made.

  12. Investigation of Water-Soluble X-ray Luminescence Nanoparticles for Photodynamic Activation

    SciTech Connect

    Liu, Yuanfang; Chen, Wei; Wang, Shaopeng; Joly, Alan G.

    2008-01-28

    In this letter, we report the synthesis of LaF3:Tb3+-MTCP (meso-Tetra(4-carboxyphenyl) porphine) nanoparticle conjugates and investigate the energy transfer as well as singlet oxygen generation following X-ray irradiation. Our observations indicate that LaF3:Tb3+-MTCP nanoparticle conjugates are efficient photodynamic agents that can be initiated by X-rays at a reasonably low dose. The addition of folic acid to facilitate targeting to folate receptors on tumor cells has no effect on the quantum yield of singlet oxygen in the nanoparticle-MTCP conjugates. Our pilot studies indicate that water-soluble scintillation nanoparticles can be potentially used to activate photodynamic therapy as a promising deep cancer treatment.

  13. Current research activities and installation status of the X-ray imaging crystal spectrometer for KSTAR

    NASA Astrophysics Data System (ADS)

    Lee, S. G.; Bak, J. G.; Nam, U. W.; Moon, M. K.; Cheon, J. K.; Bitter, M.; Hill, K.

    2008-11-01

    An X-ray imaging crystal spectrometer (XICS) for KSTAR utilizing a four-segmented position-sensitive two dimensional (2D) multi-wire proportional counter and time-to-digital converter (TDC) based delay-line readout data acquisition system has been fabricated. The XICS provides spatially and temporally resolved measurements of the ion and electron temperatures, toroidal rotation velocity, impurity charge-state distributions, and ionization equilibrium. The four-segmented 2D detector with supporting electronics successfully demonstrated to improve the photon count-rate capability of the XICS system and a position resolution of the detector showed about 0.35 mm. A spectral resolution of the fabricated spectrometer has been measured using an X-ray tube before installation in the KSTAR tokamak. The current research activities and installation status of the spectrometer will be presented.

  14. A combined optical and X-ray study of unobscured type 1 active galactic nuclei - II. Relation between X-ray emission and optical spectra

    NASA Astrophysics Data System (ADS)

    Jin, Chichuan; Ward, Martin; Done, Chris

    2012-06-01

    In this second paper in a series of three, we study the properties of the various emission features and underlying continuum in the optical spectra of type 1 active galactic nuclei (AGNs) by using the unobscured hard X-ray emission as a diagnostic. We introduce the use of the 'correlation spectrum technique' (CST) for the first time. We use this to show the strength of the correlation between the hard X-ray luminosity and each wavelength of the optical spectrum. This shows that for broad-line Seyfert 1 galaxies all the strong emission lines (the broad component of Hα and Hβ, [Ne III] λλ3869/3967, [O I] λλ6300/6364, [O II] λλ3726/3729 and [O III] λλ4959/5007) and the optical underlying continuum all strongly correlate with the hard X-ray emission. In contrast, the narrow-line Seyfert 1 galaxies show a stronger correlation in the optical continuum but a weaker correlation in the lines. A cross-correlation with luminosity between the various Balmer line components and the broad-band spectral energy distribution (SED) components shows that the best correlation exists between the hard X-ray component and the broad component (BC) of the Balmer lines. Such a correlation is weaker for the intermediate (IC) and narrow components, which supports the view that the broad-line region (BLR) has the closest link with the AGN's compact X-ray emission. The equivalent widths of the Balmer line IC and BC are found to correlate with ?, ?, Balmer line full width at half-maximum (FWHM) and black hole mass. There is a non-linear dependence of the Balmer line IC and BC luminosities with ? and L5100, which suggests that a second-order factor such as the intermediate-line region (ILR) and BLR covering factors affect the Balmer line component luminosities. The Balmer decrement is found to decrease from ˜5 in the line core to ˜2 in the extended wings, with mean decrements of 2.1 in the BLR and 4.8 in the ILR. This suggests different physical conditions in these regions, such as

  15. Ultraviolet-excess selection of the counterpart to a globular cluster X-ray burster - Hubble Space Telescope images of the core of NGC 6712

    NASA Technical Reports Server (NTRS)

    Anderson, Scott F.; Margon, Bruce; Deutsch, Eric W.; Downes, Ronald A.

    1993-01-01

    Using the Planetary Camera on the Hubble Space Telescope, we have obtained high spatial resolution, multicolor images and photometry of the core of the globular cluster NGC 6712. A comparison of our blue and ultraviolet images unambiguously reveals a faint (B = 21), UV-excess object, 'star S', within the Einstein error box for the bursting X-ray source X1850-086. The unusual color of star S is immediately apparent even in a cursory visual comparison of the images, and is more quantitatively (U-B of about -1) confirmed via photometry. A variety of different candidate optical counterparts to the X-ray source have previously been suggested from ground-based work, but our images indicate that star S is almost certainly the only viable candidate brighter than U = 21. Compared with the mean values for low mass X-ray binaries in the field, star S has a typical (U-B) color, and a moderate-to-high X-ray-to-optical luminosity ratio, but its luminosity (MB = 5) is about 4 mag fainter than average.

  16. Analysis of Active Figure Control Effects on Mounting Strategy for X-Ray Optics

    NASA Technical Reports Server (NTRS)

    Kolodziejczak, Jeffrey J.; Roche, Jacqueline M.; O'Dell, Stephen L.; Ramsey, Brian D.; Elsner, Ryan F.; Gubarev, Mikhail V.; Weisskopf, Martin C.

    2014-01-01

    As part of ongoing development efforts at MSFC, we have begun to investigate mounting strategies for highly nested x-ray optics in both full-shell and segmented configurations. The analytical infrastructure for this effort also lends itself to investigation of active strategies. We expect that a consequence of active figure control on relatively thin substrates is that errors are propagated to the edges, where they might affect the effective precision of the mounting points. Based upon modeling, we describe parametrically, the conditions under which active mounts are preferred over fixed ones, and the effect of active figure corrections on the required number, locations, and kinematic characteristics of mounting points.

  17. X-ray polarization fluctuations induced by cloud eclipses in active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Marin, F.; Dovčiak, M.

    2015-01-01

    Context. A fraction of active galactic nuclei (AGN) show dramatic X-ray spectral changes on the day-to-week time scales associated with variation in the line of sight of the cold absorber. Aims: We intend to model the polarization fluctuations arising from an obscuration event, thereby offering a method of determining whether flux variations are due to occultation or extreme intrinsic emission variability. Methods: Undertaking 1-100 keV polarimetric simulations with the Monte Carlo code Stokes, we simulated the journey of a variety of cold gas clouds in front of an extended primary source. We varied the hydrogen column density nH and size of the absorber, as well as the initial polarization state of the emitting source, to cover a wide range of scenarios. Results: Simulations indicate that different results are expected according to the initial polarization of the extended continuum source. For unpolarized primary fluxes, large (~50°) variations of the polarization position angle ψ are expected before and after an occultation event, which is associated with very low residual polarization degrees (P ≪ 1%). In the case of an emitting disk with intrinsic, position-independent polarization, and for a given range of parameters, X-ray eclipses significantly alter the observed polarization spectra, with most of the variations seen in ψ. Finally, non-uniformly polarized emitting regions produce very distinctive polarization variations due to the successive covering and uncovering of different portions of the disk. Plotted against time, variations in P and ψ form detectable P Cygni type profiles that are distinctive signatures of non-axisymmetric emission. Conclusions: We find that X-ray polarimetry is particularly adapted to probing X-ray eclipses due to Compton-thin and Compton-thick gas clouds. Polarization measurements would distinguish between intrinsic intensity fluctuations and external eclipsing events, constrain the geometry of the covering medium, and test

  18. X-ray/microwave relation of different types of active stars

    NASA Technical Reports Server (NTRS)

    Guedel, Manuel; Benz, Arnold O.

    1993-01-01

    Coronal active stars of seven classes between spectral types F and M, single and double, are compared in their quiescent radio and X-ray luminosities L(R) and L(X). We find, largely independent of stellar class, log L(X) is less than about log L(R) + 15.5. This general relation points to an intimate connection between the nonthermal, energetic electrons causing the radio emission and the bulk plasma of the corona responsible for thermal X-rays. The relation, observed over six orders of magnitude, suggests that the heating mechanism necessarily involves particle acceleration. We derive requirements for simple models based on optically thin gyrosynchrotron emission of mildly relativistic electrons and thermal X-rays from the bulk plasma. We discuss the possibility that a portion of the accelerated particles heats the ambient plasma by collisions. More likely, plasma heating and particle acceleration may occur in parallel and in the same process, but at a fixed ratio.

  19. Spectral evolution of active galactic nuclei: A unified description of the X-ray and gamma

    NASA Technical Reports Server (NTRS)

    Leiter, D.; Boldt, E.

    1982-01-01

    A model for spectral evolution is presented whereby active galactic nuclei (AGN) of the type observed individually emerge from an earlier stage at z approx = 4 in which they are the thermal X-ray sources responsible for most of the cosmic X-ray background (CXB). The conjecture is pursued that these precursor objects are initially supermassive Schwarzschild black holes with accretion disks radiating near the Eddington luminosity limit. It is noted that after approx. 10 to the 8th power years these central black holes are spun-up to a canonical Kerr equilibrium state (A/M = 0.998; Thorne 1974) and shown how they then can lead to spectral evolution involving non-thermal emission extending to gamma rays, at the expense of reduced thermal disk radiation. That major portion of the CXB remaining after the contribution of usual AGN are considered, while a superposition of AGN sources at z 1 can account for the gamma ray background. Extensive X-ray measurements carried out with the HEAO 1 and 2 missions as well as gamma ray and optical data are shown to compare favorably with principal features of this model.

  20. HERO: Program Status and Fist Images from a Balloon-Borne Focusing Hard-X-ray Telescope

    NASA Technical Reports Server (NTRS)

    Ramsey, B. D.; Alexander, C. D.; Apple, J. A.; Benson, C. M.; Dietz, K. L.; Elsner, R. F.; Engelhaupt. D. E.; Ghosh, K. K.; Kolodziejczak, J. J.; ODell, S. L.; Six, N. Frank (Technical Monitor)

    2001-01-01

    HERO is a balloon payload featuring shallow-graze angle replicated optics for hard-x-ray imaging. When completed, the instrument will offer unprecedented sensitivity in the hard-x-ray region, giving thousands of sources to choose from for detailed study on long flights. A recent proof-of-concept flight captured the first hard-x-ray focused images of the Crab Nebula, Cygnus X-1 and GRS 1915+105. Full details of the HERO program are presented, including the design and performance of the optics, the detectors and the gondola. Results from the recent proving flight are discussed together with expected future performance when the full science payload is completed.

  1. Observations of X-ray transient source GS2023+338 with the TTM coded mask telescope

    NASA Astrophysics Data System (ADS)

    Pan, H. C.; in 't Zand, J. J. M.; Skinner, G. K.; Borozdin, K. N.; Gil'Fanov, M. R.; Siuniaev, R. A.

    1993-01-01

    TTM observations in which the bright X-ray transient source GS2023+338 (=V404 Cyg) in the period June-August 1989 are reported. The observed spectral structure can be modeled using a model of a power-law source with a photon index of about 1.5, surrounded by partially ionized material. The observed X-rays consist of a component from the power-law source and those reflected (down-scattered) by the partially ionized material. Varying the clumpy structure or changing the ionization state of the circumstellar matter will cause the low-energy absorption to fluctuate.

  2. Developing fine-pixel CdTe detectors for the next generation of high-resolution hard x-ray telescopes

    NASA Astrophysics Data System (ADS)

    Christe, Steven

    -based detector system through the (1) design, manufacture, and test of front-end electronics instrument boards and (2) calibration of the detectors to assess their performance and (3) vibration and environmental testing. By the end of this program, multiple detector assemblies will be built and characterized, and can be used as part of future instruments. We propose to augment the existing effort with the development of an anti-coincidence shield for these HEXITEC-based detector assemblies to maximize sensitivity. Designing the anti-coincidence shield is enabled by the addition of a new team member, Wayne Baumgartner, who has recently and fortuitously joined the existing effort. Dr. Baumgartner has valuable and relevant past experience with a similar shield systems developed for NuSTAR and the InFOCμS x-ray telescope. We are asking for a modest amount of additional funding in this proposal year, as it coincides with a key time in the characterization and environmental testing of the detector assemblies. Characterization and environmental testing of the bare assemblies is already funded under the current effort. The addition of this active shield will allow for a more complete detector module vibration and environment test at the end of the existing development program so that this project results in a detector system with a demonstrated TRL of 6: "System/subsystem model or prototype demonstration in a relevant environment."

  3. Active galactic nucleus X-ray variability in the XMM-COSMOS survey

    SciTech Connect

    Lanzuisi, G.; Ponti, G.; Salvato, M.; Brusa, M.; Nandra, P. K.; Merloni, A.; Rosario, D.; Hasinger, G.; Sanders, D.; Cappelluti, N.; Comastri, A.; Gilli, R.; Bongiorno, A.; Lusso, E.; Steinhardt, C.; Silverman, J.; Schramm, M.; Trump, J.; and others

    2014-02-01

    We used the observations carried out by XMM in the COSMOS field over 3.5 yr to study the long term variability of a large sample of active galactic nuclei (AGNs) (638 sources) in a wide range of redshifts (0.1 < z < 3.5) and X-ray luminosities (10{sup 41} < L {sub 0.5-10} <10{sup 45.5}). Both a simple statistical method to assess the significance of variability and the Normalized Excess Variance (σ{sub rms}{sup 2}) parameter were used to obtain a quantitative measurement of the variability. Variability is found to be prevalent in most AGNs, whenever we have good statistics to measure it, and no significant differences between type 1 and type 2 AGNs were found. A flat (slope –0.23 ± 0.03) anti-correlation between σ{sub rms}{sup 2} and X-ray luminosity is found when all significantly variable sources are considered together. When divided into three redshift bins, the anti-correlation becomes stronger and evolving with z, with higher redshift AGNs being more variable. We prove, however, that this effect is due to the pre-selection of variable sources: when considering all of the sources with an available σ{sub rms}{sup 2} measurement, the evolution in redshift disappears. For the first time, we were also able to study long term X-ray variability as a function of M {sub BH} and Eddington ratio for a large sample of AGNs spanning a wide range of redshifts. An anti-correlation between σ{sub rms}{sup 2} and M {sub BH} is found, with the same slope of anti-correlation between σ{sub rms}{sup 2} and X-ray luminosity, suggesting that the latter may be a by-product of the former. No clear correlation is found between σ{sub rms}{sup 2} and the Eddington ratio in our sample. Finally, no correlation is found between the X-ray σ{sub rms}{sup 2} and optical variability.

  4. Centroiding and point response function measurements of the mirror/detector combination for the x-ray telescope on the SWIFT gamma-ray burst explorer

    NASA Astrophysics Data System (ADS)

    Ambrosi, Richard M.; Abbey, Anthony F.; Hutchinson, Ian; Willingale, Richard; Campana, Sergio; Cusumano, G.; Burkert, Wolfgang; Wells, Alan A.; Short, Alexander T.; Citterio, Oberto; Ghigo, Mauro; Tagliaferri, G.; Braeuninger, Heinrich W.

    2002-01-01

    The essential optical components of the Swift X-ray Telescope (XRT) are already developed items. They are: the flight spare x-ray mirror from the JET-X/Spectrum-X program and a MOS CCD (CCD22) of the type currently operating in orbit as part of the EPIC focal plane camera on the XMM- Newton. The JET-X mirrors were first calibrated at the Max Plank Institute for Extraterrestrial Physics' (MPE) Panter facility, Garching, Germany in 1996. Half energy widths (HEW) of 16 arc seconds at 1.5 keV were confirmed for the two flight mirrors and the flight spare. The calibration of the flight spare was repeated at Panter in July 2000 in order to establish whether any changes had occurred during the four years that the mirror had been in storage at the OAB, Milan, Italy. This results reported in this paper, confirm that the resolution of the JET-X mirrors has remained stable over this storage period. In an extension of this test program, the flight spare EPIC camera was installed at the focus of the JET-X mirror to simulate the optical system of the Swift X-ray telescope. On-axis and off-axis point spread functions (PSFs) were measured and calibration data sets were used to obtain centroid positions of X-ray point sources. The results confirmed Swift's ability to determine the centroid positions of sources at 100mCrab brightness to better than 1 arc second and provided a calibration of the centroiding process as a function of source flux and off axis angle. The presence of background events in the image frame introduced errors in the centroiding process, making the choice of centroiding algorithm important. Algorithm performance and the trade-off between processing speed and centroiding accuracy were investigated.

  5. Barbiturate bearing aroylhydrazine derivatives: Synthesis, NMR investigations, single crystal X-ray studies and biological activity

    NASA Astrophysics Data System (ADS)

    Giziroglu, Emrah; Sarikurkcu, Cengiz; Aygün, Muhittin; Basbulbul, Gamze; Soyleyici, H. Can; Firinci, Erkan; Kirkan, Bulent; Alkis, Ayse; Saylica, Tayfur; Biyik, Halil

    2016-03-01

    A series of barbituric acid aroylhydrazine derivatives have been prepared from their corresponding 1,3-dimethyl-5-acetyl barbituric acid and aroylhydrazines. All compounds have been fully characterized by using FT-IR, multinuclear NMR (1H, 13C) and Mass (MS) spectrometry. We also describe the X-ray crystal structure of 3a, which crystallizes in the monoclinic P21/n space group. The crystal structure is stabilized with infinite linear chains of dimeric units. Furthermore, all compounds were investigated for their tyrosinase inhibition, antioxidative and antimicrobial activies. The results from biological activity assays have shown that all of compounds have excellent antioxidant, significant tyrosinase inhibition and moderate antimicrobial activity.

  6. X-ray generator

    DOEpatents

    Dawson, John M.

    1976-01-01

    Apparatus and method for producing coherent secondary x-rays that are controlled as to direction by illuminating a mixture of high z and low z gases with an intense burst of primary x-rays. The primary x-rays are produced with a laser activated plasma, and these x-rays strip off the electrons of the high z atoms in the lasing medium, while the low z atoms retain their electrons. The neutral atoms transfer electrons to highly excited states of the highly striped high z ions giving an inverted population which produces the desired coherent x-rays. In one embodiment, a laser, light beam provides a laser spark that produces the intense burst of coherent x-rays that illuminates the mixture of high z and low z gases, whereby the high z atoms are stripped while the low z ones are not, giving the desired mixture of highly ionized and neutral atoms. To this end, the laser spark is produced by injecting a laser light beam, or a plurality of beams, into a first gas in a cylindrical container having an adjacent second gas layer co-axial therewith, the laser producing a plasma and the intense primary x-rays in the first gas, and the second gas containing the high and low atomic number elements for receiving the primary x-rays, whereupon the secondary x-rays are produced therein by stripping desired ions in a neutral gas and transfer of electrons to highly excited states of the stripped ions from the unionized atoms. Means for magnetically confining and stabilizing the plasma are disclosed for controlling the direction of the x-rays.

  7. CHANG'E-3 Active Particle-induced X-ray Spectrometer: The synthesis design and performance

    NASA Astrophysics Data System (ADS)

    Cui, XingZhu; Peng, Wenxi; Wang, Huanyu; Liang, XiaoHua

    the Active Particle X-ray Spectrometer (APXS) was designed to deduce the elemental abundances of samples on the moon. Similar to the Alpha Particle X-ray Spectrometers onboard MSL and MER , the APXS was also an instrument took the advantage of X-ray fluorescence mechanism to determine elemental abundances, it determines the chemical compositions of both soil and rocks along the traverse of the rover. To provide a sound instrument working on the lunar surface,Four components were integrated in the APXS, the performances of the components were described in this paper.

  8. Determination of carrier yields for neutron activation analysis using energy dispersive X-ray spectrometry

    USGS Publications Warehouse

    Johnson, R.G.; Wandless, G.A.

    1984-01-01

    A new method is described for determining carrier yield in the radiochemical neutron activation analysis of rare-earth elements in silicate rocks by group separation. The method involves the determination of the rare-earth elements present in the carrier by means of energy-dispersive X-ray fluorescence analysis, eliminating the need to re-irradiate samples in a nuclear reactor after the gamma ray analysis is complete. Results from the analysis of USGS standards AGV-1 and BCR-1 compare favorably with those obtained using the conventional method. ?? 1984 Akade??miai Kiado??.

  9. Synchrotron based X-ray fluorescence activities at Indus-2: An overview

    SciTech Connect

    Tiwari, M. K.

    2014-04-24

    X-Ray fluorescence (XRF) spectrometry is a powerful non-destructive technique for elemental analysis of materials at bulk and trace concentration levels. Taking into consideration several advantages of the synchrotron based XRF technique and to fulfill the requirements of Indian universities users we have setup a microfocus XRF beamline (BL-16) on Indus-2 synchrotron light source. The beamline offers a wide range of usages – both from research laboratories and industries; and for researchers working in diverse fields. A brief overview of the measured performance of the beamline, design specifications including various attractive features and recent research activities carried out on the BL-16 beamline are presented.

  10. Ensemble X-ray variability of active galactic nuclei at intermediate and long time lags

    NASA Astrophysics Data System (ADS)

    Vagnetti, Fausto; Middei, Riccardo

    2016-08-01

    We present a variability analysis for a sample of 2700 active galactic nuclei extracted from the latest release of the XMM-Newton serendipitous source catalogue. The structure function of this sample increases up to rest-frame time lags of about 5 years. Moreover, comparing observations performed by the XMM-Newton and ROSAT satellites, we are able to extend the X-ray structure function to 20 years rest-frame, showing a further increase of variability without any evidence of a plateau. Our results are compared with similar analyses in the optical band, and discussed in relation to the physical sizes of the emitting regions.

  11. Slip Activity in Single Grains Extracted from Polycrystalline Specimen by X-Ray Line Broadening (Preprint)

    DTIC Science & Technology

    2010-01-01

    4 6 8 0.005 0.010 -101-3 -110-2 1-10-2F W H M [ 1 /n m ] K [ 1/nm ] Gr #44 Gr #50 Gr #72 -101-1 1-101 (a...0 2 4 6 0.000 0.005 0.010 (b) K2Ccalc [ 1/nm ] FW H M [ 1 /n m ] Gr #44 Gr #50 Gr #72 17 Figure 5. The FWHM (in 1/nm scales) in...Preprint 01 January 2010 – 01 January 2010 4 . TITLE AND SUBTITLE SLIP ACTIVITY IN SINGLE GRAINS EXTRACTED FROM POLYCRYSTALLINE SPECIMEN BY X-RAY

  12. CHANG'E-3 Active Particle-induced X-ray Spectrometer: ground verification test

    NASA Astrophysics Data System (ADS)

    Guo, Dongya; Peng, Wenxi; Cui, XingZhu; Wang, Huanyu

    The Active Particle-induced X-ray Spectrometer (APXS) is one of the payloads of Chang’E-3 rover Yutu, with which the major elemental composition of lunar soils and rocks can be measured on site. In order to assess the instrument performance and the accuracy of determination, ground verification test was carried out with two blind samples(basaltic rock, powder). Details of the experiments and data analysis method are discussed. The results show that the accuracy of quantitative analysis for major elements(Mg,Al,Si,K,Ca,Ti,Fe) is better than 15%.

  13. Coordinated Observations of X-ray and High-resolution EUV Active Region Dynamics

    NASA Technical Reports Server (NTRS)

    Savage, Sabrina

    2013-01-01

    The recently-launched High-resolution Coronal imager (Hi-C) sounding rocket provided the highest resolution images of coronal loops and other small-scale structures in the 193 Angstrom passband to date. With just 5 minutes of observations, the instrument recorded a variety of dynamic coronal events -- including even a small B-class flare. We will present our results comparing these extreme-ultraviolet (EUV) observations with X-ray imaging from Hinode/XRT as well as EUV AIA data to identify sources of hot plasma rooted in the photosphere and track their affect on the overall topology and dynamics of the active region.

  14. Coordinated Observations of X-ray and High-Resolution EUV Active Region Dynamics

    NASA Technical Reports Server (NTRS)

    Savage, Sabrina; Cirtain, Jonathan; Winebarger, Amy; Kobayashi, Ken; Golub, Leon; Korreck, Kelly

    2013-01-01

    The recently-launched High-resolution Coronal imager (Hi-C) sounding rocket provided the highest resolution images of coronal loops and other small-scale structures in the 193 Angstrom passband to date. With just 5 minutes of observations, the instrument recorded a variety of dynamic coronal events -- including even a small B-class flare. We will present our results comparing these extreme-ultraviolet (EUV) observations with X-ray imaging from Hinode/XRT as well as EUV AIA data to identify sources of hot plasma rooted in the photosphere and track their affect on the overall topology and dynamics of the active region.

  15. X-ray crystallography

    NASA Technical Reports Server (NTRS)

    2001-01-01

    X-rays diffracted from a well-ordered protein crystal create sharp patterns of scattered light on film. A computer can use these patterns to generate a model of a protein molecule. To analyze the selected crystal, an X-ray crystallographer shines X-rays through the crystal. Unlike a single dental X-ray, which produces a shadow image of a tooth, these X-rays have to be taken many times from different angles to produce a pattern from the scattered light, a map of the intensity of the X-rays after they diffract through the crystal. The X-rays bounce off the electron clouds that form the outer structure of each atom. A flawed crystal will yield a blurry pattern; a well-ordered protein crystal yields a series of sharp diffraction patterns. From these patterns, researchers build an electron density map. With powerful computers and a lot of calculations, scientists can use the electron density patterns to determine the structure of the protein and make a computer-generated model of the structure. The models let researchers improve their understanding of how the protein functions. They also allow scientists to look for receptor sites and active areas that control a protein's function and role in the progress of diseases. From there, pharmaceutical researchers can design molecules that fit the active site, much like a key and lock, so that the protein is locked without affecting the rest of the body. This is called structure-based drug design.

  16. Proposal to National Aeronautics and Space Administration for continuation of a grazing incidence imaging telescope for X-ray astronomy using sounding rockets

    NASA Technical Reports Server (NTRS)

    Murray, B.

    1976-01-01

    The construction of a high resolution imaging telescope experiment payload suitable for launch on an Astrobee F sounding rocket was proposed. Also integration, launch, and subsequent data analysis effort were included. The payload utilizes major component subassemblies from the HEAO-B satellite program which were nonflight development units for that program. These were the X ray mirror and high resolution imager brassboard detector. The properties of the mirror and detector were discussed. The availability of these items for a sounding rocket experiment were explored with the HEAO-B project office.

  17. Testing of the Mirrors for the Constellation-X Spectroscopy X-ray Telescope with a Refractive Null

    NASA Technical Reports Server (NTRS)

    Lehan, John; Hadimichael, T.; Skocik, C.

    2007-01-01

    We present an introduction to the use of a refractive null lens for testing grazing incidence x-ray mirrors for the Constellation-X mission. The singular role of mirror mounting in glass shell mirror metrology is also touched upon. We compare results achieved to date with mission requirements along with some of the unique properties of the null lens. Additionally, uses beyond mirror metrology are briefly discussed.

  18. X-ray irradiation activates K+ channels via H2O2 signaling.

    PubMed

    Gibhardt, Christine S; Roth, Bastian; Schroeder, Indra; Fuck, Sebastian; Becker, Patrick; Jakob, Burkhard; Fournier, Claudia; Moroni, Anna; Thiel, Gerhard

    2015-09-09

    Ionizing radiation is a universal tool in tumor therapy but may also cause secondary cancers or cell invasiveness. These negative side effects could be causally related to the human-intermediate-conductance Ca2+-activated-K+-channel (hIK), which is activated by X-ray irradiation and affects cell proliferation and migration. To analyze the signaling cascade downstream of ionizing radiation we use genetically encoded reporters for H2O2 (HyPer) and for the dominant redox-buffer glutathione (Grx1-roGFP2) to monitor with high spatial and temporal resolution, radiation-triggered excursions of H2O2 in A549 and HEK293 cells. The data show that challenging cells with ≥1 Gy X-rays or with UV-A laser micro-irradiation causes a rapid rise of H2O2 in the nucleus and in the cytosol. This rise, which is determined by the rate of H2O2 production and glutathione-buffering, is sufficient for triggering a signaling cascade that involves an elevation of cytosolic Ca2+ and eventually an activation of hIK channels.

  19. X-ray irradiation activates K+ channels via H2O2 signaling

    PubMed Central

    Gibhardt, Christine S.; Roth, Bastian; Schroeder, Indra; Fuck, Sebastian; Becker, Patrick; Jakob, Burkhard; Fournier, Claudia; Moroni, Anna; Thiel, Gerhard

    2015-01-01

    Ionizing radiation is a universal tool in tumor therapy but may also cause secondary cancers or cell invasiveness. These negative side effects could be causally related to the human-intermediate-conductance Ca2+-activated-K+-channel (hIK), which is activated by X-ray irradiation and affects cell proliferation and migration. To analyze the signaling cascade downstream of ionizing radiation we use genetically encoded reporters for H2O2 (HyPer) and for the dominant redox-buffer glutathione (Grx1-roGFP2) to monitor with high spatial and temporal resolution, radiation-triggered excursions of H2O2 in A549 and HEK293 cells. The data show that challenging cells with ≥1 Gy X-rays or with UV-A laser micro-irradiation causes a rapid rise of H2O2 in the nucleus and in the cytosol. This rise, which is determined by the rate of H2O2 production and glutathione-buffering, is sufficient for triggering a signaling cascade that involves an elevation of cytosolic Ca2+ and eventually an activation of hIK channels. PMID:26350345

  20. Low dose X -ray effects on catalase activity in animal tissue

    NASA Astrophysics Data System (ADS)

    Focea, R.; Nadejde, C.; Creanga, D.; Luchian, T.

    2012-12-01

    This study was intended to investigate the effect of low-dose X ray-irradiation upon the activity of catalase (CAT) in freshly excised chicken tissues (liver, kidney, brain, muscle). The tissue samples were irradiated with 0.5Gy and 2Gy respectively, in a 6 MV photon beam produced by a clinical linear accelerator (VARIAN CLINAC 2100SC). The dose rate was of 260.88cGy/min. at 100 cm source to sample distance. The catalase level was assayed spectrophotometrically, based on reaction kinetics, using a catalase UV assay kit (SIGMA). Catalase increased activity in various tissue samples exposed to the studied X ray doses (for example with 24 % in the liver cells, p<0.05) suggested the stimulation of the antioxidant enzyme biosynthesis within several hours after exposure at doses of 0.5 Gy and 2 Gy; the putative enzyme inactivation could also occur (due to the injuries on the hydrogen bonds that ensure the specificity of CAT active site) but the resulted balance of the two concurrent processes indicates the cell ability of decomposing the hydrogen peroxide-with benefits for the cell physiology restoration for the chosen low dose radiation.

  1. The front-end electronics of the Spectrometer Telescope for Imaging X-Rays (STIX) on the ESA Solar Orbiter satellite

    NASA Astrophysics Data System (ADS)

    Grimm, O.; Bednarzik, M.; Commichau, V.; Graczyk, R.; Gröbelbauer, H. P.; Hurford, G.; Krucker, S.; Limousin, O.; Meuris, A.; Orleański, P.; Przepiórka, A.; Seweryn, K.; Skup, K.; Viertel, G.

    2012-12-01

    Solar Orbiter is an ESA mission to study the heliosphere in proximity to the Sun, scheduled for launch in January 2017. It carries a suite of ten instruments for comprehensive remote-sensing and in-situ measurements. The Spectrometer Telescope for Imaging X-Rays (STIX), one of the remote sensing instruments, images X-rays between 4 and 150keV using an Fourier technique. The angular resolution is 7 arcsec and the spectral resolution 1keV full-width-half-maximum at 6keV. X-ray detection uses pixelized Cadmium Telluride crystals provided by the Paul Scherrer Institute. The crystals are bonded to read-out hybrids developed by CEA Saclay, called Caliste-SO, incorporating a low-noise, low-power analog front-end ASIC IDeF-X HD. The crystals are cooled to -20°C to obtain very low leakage currents of less than 60pA per pixel, the prerequisite for obtaining the required spectral resolution. This article briefly describes the mission goals and then details the front-end electronics design and main challenges, resulting in part from the allocation limit in mass of 7kg and in power of 4W. Emphasis is placed on the design influence of the cooling requirement within the warm environment of a mission approaching the Sun to within the orbit of Mercury. The design for the long-term in-flight energy calibration is also explained.

  2. Energetic electrons, hard x-ray emission and MHD activity studies in the IR-T1 tokamak.

    PubMed

    Agah, K Mikaili; Ghoranneviss, M; Elahi, A Salar

    2015-01-01

    Determinations of plasma parameters as well as the Magnetohydrodynamics (MHD) activity, energetic electrons energy and energy confinement time are essential for future fusion reactors experiments and optimized operation. Also some of the plasma information can be deduced from these parameters, such as plasma equilibrium, stability, and MHD instabilities. In this contribution we investigated the relation between energetic electrons, hard x-ray emission and MHD activity in the IR-T1 Tokamak. For this purpose we used the magnetic diagnostics and a hard x-ray spectroscopy in IR-T1 tokamak. A hard x-ray emission is produced by collision of the runaway electrons with the plasma particles or limiters. The mean energy was calculated from the slope of the energy spectrum of hard x-ray photons.

  3. Soft X-Ray Excess from Shocked Accreting Plasma in Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Fukumura, Keigo; Hendry, Douglas; Clark, Peter; Tombesi, Francesco; Takahashi, Masaaki

    2016-08-01

    We propose a novel theoretical model to describe the physical identity of the soft X-ray excess that is ubiquitously detected in many Seyfert galaxies, by considering a steady-state, axisymmetric plasma accretion within the innermost stable circular orbit around a black hole (BH) accretion disk. We extend our earlier theoretical investigations on general relativistic magnetohydrodynamic accretion, which implied that the accreting plasma can develop into a standing shock under suitable physical conditions, causing the downstream flow to be sufficiently hot due to shock compression. We perform numerical calculations to examine, for sets of fiducial plasma parameters, the physical nature of fast magnetohydrodynamic shocks under strong gravity for different BH spins. We show that thermal seed photons from the standard accretion disk can be effectively Compton up-scattered by the energized sub-relativistic electrons in the hot downstream plasma to produce the soft excess feature in X-rays. As a case study, we construct a three-parameter Comptonization model of inclination angle θ obs, disk photon temperature kT in, and downstream electron energy kT e to calculate the predicted spectra in comparison with a 60 ks XMM-Newton/EPIC-pn spectrum of a typical radio-quiet Seyfert 1 active galactic nucleus, Ark 120. Our χ 2-analyses demonstrate that the model is plausible for successfully describing data for both non-spinning and spinning BHs with derived ranges of 61.3 keV ≲ kT e ≲ 144.3 keV, 21.6 eV ≲ kT in ≲ 34.0 eV, and 17.°5 ≲ θ obs ≲ 42.°6, indicating a compact Comptonizing region of three to four gravitational radii that resembles the putative X-ray coronae.

  4. Feedback from Mass Outflows in Nearby Active Galactic Nuclei. I. Ultraviolet and X-Ray Absorbers

    NASA Astrophysics Data System (ADS)

    Crenshaw, D. M.; Kraemer, S. B.

    2012-07-01

    We present an investigation into the impact of feedback from outflowing UV and X-ray absorbers in nearby (z < 0.04) active galactic nuclei (AGNs). From studies of the kinematics, physical conditions, and variability of the absorbers in the literature, we calculate the possible ranges in the total mass outflow rate (\\dot{M}_{out}) and kinetic luminosity (L KE) for each AGN, summed over all of its absorbers. These calculations make use of values (or limits) for the radial locations of the absorbers determined from variability, excited-state absorption, and other considerations. From a sample of 10 Seyfert 1 galaxies with detailed photoionization models for their absorbers, we find that 7 have sufficient constraints on the absorber locations to determine \\dot{M}_{out} and L KE. For the low-luminosity AGN NGC 4395, these values are low, although we do not have sufficient constraints on the X-ray absorbers to make definitive conclusions. At least five of the six Seyfert 1s with moderate bolometric luminosities (L bol = 1043 - 1045 erg s-1) have mass outflow rates that are 10-1000 times the mass accretion rates needed to generate their observed luminosities, indicating that most of the mass outflow originates from outside the inner accretion disk. Three of these (NGC 4051, NGC 3516, and NGC 3783) have L KE in the range 0.5%-5% L bol, which is the range typically required by feedback models for efficient self-regulation of black hole and galactic bulge growth. At least two of the other three (NGC 5548, NGC 4151, and NGC 7469) have L KE >~ 0.1%L bol, although these values may increase if radial locations can be determined for more of the absorbers. We conclude that the outflowing UV and X-ray absorbers in moderate-luminosity AGNs have the potential to deliver significant feedback to their environments.

  5. An X-ray spectral model for clumpy tori in active galactic nuclei

    SciTech Connect

    Liu, Yuan; Li, Xiaobo E-mail: lixb@ihep.ac.cn

    2014-05-20

    We construct an X-ray spectral model for the clumpy torus in an active galactic nucleus (AGN) using Geant4, which includes the physical processes of the photoelectric effect, Compton scattering, Rayleigh scattering, γ conversion, fluorescence line, and Auger process. Since the electrons in the torus are expected to be bounded instead of free, the deviation of the scattering cross section from the Klein-Nishina cross section has also been included, which changes the X-ray spectra by up to 25% below 10 keV. We have investigated the effect of the clumpiness parameters on the reflection spectra and the strength of the fluorescent line Fe Kα. The volume filling factor of the clouds in the clumpy torus only slightly influences the reflection spectra, however, the total column density and the number of clouds along the line of sight significantly change the shapes and amplitudes of the reflection spectra. The effect of column density is similar to the case of a smooth torus, while a small number of clouds along the line of sight will smooth out the anisotropy of the reflection spectra and the fluorescent line Fe Kα. The smoothing effect is mild in the low column density case (N {sub H} = 10{sup 23} cm{sup –2}), whereas it is much more evident in the high column density case (N {sub H} = 10{sup 25} cm{sup –2}). Our model provides a quantitative tool for the spectral analysis of the clumpy torus. We suggest that the joint fits of the broad band spectral energy distributions of AGNs (from X-ray to infrared) should better constrain the structure of the torus.

  6. High Resolution X-ray Imaging

    NASA Technical Reports Server (NTRS)

    Cash, Webster

    2002-01-01

    NAG5-5020 covered a period of 7.5 years during which a great deal of progress was made in x-ray optical techniques under this grant. We survived peer review numerous times during the effort to keep the grant going. In 1994, when the grant started we were actively pursuing the application of spherical mirrors to improving x-ray telescopes. We had found that x-ray detectors were becoming rapidly more sophisticated and affordable, but that x-ray telescopes were only being improved through the intense application of money within the AXAF program. Clearly new techniques for the future were needed. We were successful in developing and testing at the HELSTF facility in New Mexico a four reflection coma-corrected telescope made from spheres. We were able to demonstrate 0.3 arcsecond resolution, almost to the diffraction limit of the system. The community as a whole was, at that time, not particularly interested in looking past AXAF (Chandra) and the effort needed to evolve. Since we had reached the diffraction limit using non-Wolter optics we then decided to see if we could build an x-ray interferometer in the laboratory. In the lab the potential for improved resolution was substantial. If synthetic aperture telescopes could be built in space, then orders of magnitude improvement would become feasible. In 1998 NASA, under the direction of Dr. Nick White of Goddard, started a study to assess the potential and feasibility of x-ray interferometry in space. My work became of central interest to the committee because it indicated that such was possible. In early 1999 we had the breakthrough that allowed us build a practical interferometer. By using flats and hooking up with the Marshall Space Flight Center facilities we were able to demonstrate fringes at 1.25keV on a one millimeter baseline. This actual laboratory demonstration provided the solid proof of concept that NASA needed.

  7. The subarcsecond mid-infrared view of local active galactic nuclei - II. The mid-infrared-X-ray correlation

    NASA Astrophysics Data System (ADS)

    Asmus, D.; Gandhi, P.; Hönig, S. F.; Smette, A.; Duschl, W. J.

    2015-11-01

    We present an updated mid-infrared (MIR) versus X-ray correlation for the local active galactic nuclei (AGN) population based on the high angular resolution 12 and 18μm continuum fluxes from the AGN subarcsecond MIR atlas and 2-10 keV and 14-195 keV data collected from the literature. We isolate a sample of 152 objects with reliable AGN nature and multi-epoch X-ray data and minimal MIR contribution from star formation. Although the sample is not homogeneous or complete, we show that our results are unlikely to be affected by significant biases. The MIR-X-ray correlation is nearly linear and within a factor of 2 independent of the AGN type and the wavebands used. The observed scatter is <0.4 dex. A possible flattening of the correlation slope at the highest luminosities probed (˜1045 erg s-1) towards low MIR luminosities for a given X-ray luminosity is indicated but not significant. Unobscured objects have, on average, an MIR-X-ray ratio that is only ≤0.15 dex higher than that of obscured objects. Objects with intermediate X-ray column densities (22 < log NH < 23) actually show the highest MIR-X-ray ratio on average. Radio-loud objects show a higher mean MIR-X-ray ratio at low luminosities while the ratio is lower than average at high luminosities. This may be explained by synchrotron emission from the jet contributing to the MIR at low luminosities and additional X-ray emission at high luminosities. True Seyfert 2 candidates do not show any deviation from the general behaviour suggesting that they possess a dusty obscurer as in other AGN. Double AGN also do not deviate. Finally, we show that the MIR-X-ray correlation can be used to investigate the AGN nature of uncertain objects. Specifically, we give equations that allow us to determine the intrinsic 2-10 keV luminosities and column densities for objects with complex X-ray properties to within 0.34 dex. These techniques are applied to the uncertain objects of the remaining AGN MIR atlas, demonstrating the

  8. X-RAY ACTIVE MATRIX PIXEL SENSORS BASEDON J-FET TECHNOLOGY DEVELOPED FOR THE LINAC COHERENT LIGHT SOURCE.

    SciTech Connect

    CARINI,G.A.; CHEN, W.; LI, Z.; REHAK, P.; SIDDONS, D.P.

    2007-10-29

    An X-ray Active Matrix Pixel Sensor (XAMPS) is being developed for recording data for the X-ray Pump Probe experiment at the Linac Coherent Light Source (LCLS). Special attention has to be paid to some technological challenges that this design presents. New processes were developed and refined to address problems encountered during previous productions of XAMPS. The development of these critical steps and corresponding tests results are reported here.

  9. The corona of HD 189733 and its X-ray activity

    SciTech Connect

    Pillitteri, I.; Wolk, S. J.; Günther, H. M.; Cohen, O.; Kashyap, V.; Drake, J. J.; Lopez-Santiago, J.; Sciortino, S.

    2014-04-20

    Testing whether close-in massive exoplanets (hot Jupiters) can enhance the stellar activity in their host primary is crucial for the models of stellar and planetary evolution. Among systems with hot Jupiters, HD 189733 is one of the best studied because of its proximity, strong activity, and the presence of a transiting planet, which allows transmission spectroscopy and a measure of the planetary radius and its density. Here we report on the X-ray activity of the primary star, HD 189733 A, using a new XMM-Newton observation and a comparison with the previous X-ray observations. The spectrum in the quiescent intervals is described by two temperatures at 0.2 keV and 0.7 keV, while during the flares a third component at 0.9 keV is detected. With the analysis of the summed Reflection Grating Spectrometer spectra, we obtain estimates of the electron density in the range n{sub e} = (1.6-13) × 10{sup 10} cm{sup –3}, and thus the corona of HD 189733 A appears denser than the solar one. For the third time, we observe a large flare that occurred just after the eclipse of the planet. Together with the flares observed in 2009 and 2011, the events are restricted to a small planetary phase range of φ = 0.55-0.65. Although we do not find conclusive evidence of a significant excess of flares after the secondary transits, we suggest that the planet might trigger such flares when it passes close to the locally high magnetic field of the underlying star at particular combinations of stellar rotational phases and orbital planetary phases. For the most recent flares, a wavelet analysis of the light curve suggests a loop of length of four stellar radii at the location of the bright flare, and a local magnetic field of the order of 40-100 G, in agreement with the global field measured in other studies. The loop size suggests an interaction of magnetic nature between planet and star, separated by only ∼8R {sub *}. The X-ray variability of HD 189733 A is larger than the variability

  10. Analysis of Chandra X-ray Spectra of the Young, Active Star AB Dor

    NASA Astrophysics Data System (ADS)

    Linsky, J. L.; Gagne, M.

    2001-05-01

    The early-K dwarf AB Dor is a nearby (15 pc), young (20--30 Myr), rapidly rotating (Prot = 0.514 day) star with saturated X-ray emission (Lx/Lbol ~ 10-3) and cool prominence-like gas extending several stellar radii into its corona. We observed this extensively studied star on 1999 Oct 9 for 60 ks with the high energy transmission grating (HETG/ACIS-S) on Chandra. The rich X-ray spectra contain emission lines of N, O, Ne, Mg, Al, Si, S, Ar, Ca, Fe, and Ni. As is seen in other active stars, the Ne abundance is high and the Fe abundance low compared to solar photospheric abundances, indicating the reverse of the enhanced first ionization potential (FIP) effect seen in the solar corona. The emission measure distribution shows peaks near log T = 6.8 and 7.3, and the helium-like triplets of O VII, Ne IX, and Mg XI indicate electron densities log ne ~ 11.0. We will use these data to infer the size and properties of coronal loops in the stellar corona. We find no noticeable line shifts indicative of a wind or downflows. This GTO Chandra program is supported by NASA through a grant to NIST and the University of Colorado.

  11. LOW-MASS ACTIVE GALACTIC NUCLEI WITH RAPID X-RAY VARIABILITY

    SciTech Connect

    Ho, Luis C.; Kim, Minjin

    2016-04-10

    We present a detailed study of the optical spectroscopic properties of 12 active galactic nuclei (AGNs) with candidate low-mass black holes (BHs) selected by Kamizasa et al. through rapid X-ray variability. The high-quality, echellette Magellan spectra reveal broad Hα emission in all the sources, allowing us to estimate robust virial BH masses and Eddington ratios for this unique sample. We confirm that the sample contains low-mass BHs accreting at high rates: the median M{sub BH} = 1.2 × 10{sup 6} M{sub ⊙} and median L{sub bol}/L{sub Edd} = 0.44. The sample follows the M{sub BH}–σ{sub *} relation, within the considerable scatter typical of pseudobulges, the probable hosts of these low-mass AGNs. Various lines of evidence suggest that ongoing star formation is prevalent in these systems. We propose a new strategy to estimate star formation rates in AGNs hosted by low-mass, low-metallicity galaxies, based on modification of an existing method using the strength of [O ii] λ3727, [O iii] λ5007, and X-rays.

  12. In vivo monitoring of toxic metals: assessment of neutron activation and x-ray fluorescence techniques

    SciTech Connect

    Ellis, K.J.

    1986-01-01

    To date, cadmium, lead, aluminum, and mercury have been measured in vivo in humans. The possibilities of monitoring other toxic metals have also been demonstrated, but no human studies have been performed. Neutron activation analysis appears to be most suitable for Cd and Al measurements, while x-ray fluorescence is ideally suited for measurement of lead in superficial bone. Filtered neutron beams and polarized x-ray sources are being developed which will improve in vivo detection limits. Even so, several of the current facilities are already suitable for use in epidemiological studies of selected populations with suspected long-term low-level ''environmental'' exposures. Evaluation and diagnosis of patients presenting with general clinical symptoms attributable to possible toxic metal exposure may be assisted by in vivo examination. Continued in vivo monitoring of industrial workers, especially follow-up measurements, will provide the first direct assessment of changes in body burden and a direct measure of the biological life-times of these metals in humans. 50 refs., 4 figs., 2 tabs.

  13. pn-CCDs in a low-background environment: detector background of the CAST x-ray telescope

    NASA Astrophysics Data System (ADS)

    Kuster, M.; Cebrián, S.; Rodríquez, A.; Kotthaus, R.; Bräuninger, H.; Franz, J.; Friedrich, P.; Hartmann, R.; Kang, D.; Lutz, G.; Strüder, L.

    2005-08-01

    The CAST experiment at CERN (European Organization of Nuclear Research) searches for axions from the sun. The axion is a pseudoscalar particle that was motivated by theory thirty years ago, with the intention to solve the strong CP problem. Together with the neutralino, the axion is one of the most promising dark matter candidates. The CAST experiment has been taking data during the last two years, setting an upper limit on the coupling of axions to photons more restrictive than from any other solar axion search in the mass range below 10-1 eV. In 2005 CAST will enter a new experimental phase extending the sensitivity of the experiment to higher axion masses. The CAST experiment strongly profits from technology developed for high energy physics and for X-ray astronomy: A superconducting prototype LHC magnet is used to convert potential axions to detectable X-rays in the 1-10 keV range via the inverse Primakoff effect. The most sensitive detector system of CAST is a spin-off from space technology, aWolter I type X-ray optics in combination with a prototype pn-CCD developed for ESA's XMM-Newton mission. As in other rare event searches, background suppression and a thorough shielding concept is essential to improve the sensitivity of the experiment to the best possible. In this context CAST offers the opportunity to study the background of pn-CCDs and its long term behavior in a terrestrial environment with possible implications for future space applications. We will present a systematic study of the detector background of the pn-CCD of CAST based on the data acquired since 2002 including preliminary results of our background simulations.

  14. The Global Implications of the Hard X-Ray Excess in Type 1 Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Tatum, M.; Turner, J.; Miller, L.; Reeves, J.

    2014-07-01

    The Suzaku observations of 1H 0419-577 and PDS 456 revealed a marked excess of flux above 10 keV, dubbed a 'hard excess'. In both sources, the high PIN-band flux was explained by the presence of a Compton-thick absorber covering > 70% of the continuum source. These results motivated an exploratory study of the hard excess phenomenon in the local type 1 AGN population, using the Swift Burst Alert Telescope (BAT). We selected all type 1 AGN, including intermediates up to type 1.9, from the 58-month BAT catalog. To understand the sample properties, we required simultaneous medium (2-10 keV) and hard X-ray (>10 keV) data. Therefore, we cross-correlated those selected sources with the Suzaku archive. From our sample, we extracted the observed energy density fluxes for the 2-10 keV and 15-50 keV bandpasses to determine the hardness ratio, Flux(15-50)/Flux(2-10), and extracted the equivalent width of the narrow core of Fe K alpha emission for each observation. We found that a partial-covering, Compton-thick absorber model is the most consistent with the observational result. In this talk, we discuss our methodology, the observational finding, and the location of the Compton-thick gas and its relationship to the optical broad-line region.

  15. Crystallization and Preliminary X-Ray Crystallographic Analysis of Human Plasma Platelet Activating Factor Acetylhydrolase

    SciTech Connect

    Samanta, U.; Wilder, C; Bahnson, B

    2009-01-01

    The plasma form of the human enzyme platelet activating factor acetylhydrolase (PAF-AH) has been crystallized, and X-ray diffraction data were collected at a synchrotron source to a resolution of 1.47 {angstrom}. The crystals belong to space group C2, with unit cell parameters of a = 116.18, b = 83.06, c = 96.71 {angstrom}, and {beta} = 115.09 and two molecules in the asymmetric unit. PAF-AH functions as a general anti-inflammatory scavenger by reducing the levels of the signaling molecule PAF. Additionally, the LDL bound enzyme has been linked to atherosclerosis due to its hydrolytic activities of pro-inflammatory agents, such as sn-2 oxidatively fragmented phospholipids.

  16. Chandra Space Flight Software: Using Software to Autonomously Operation the Largest and Most Sensitive X-Ray Telescope in the World

    NASA Technical Reports Server (NTRS)

    Crumbley, Tim; Stevens, Robert L. (Technical Monitor)

    2001-01-01

    Chandra is the world's largest and most sensitive X-ray telescope. The Chandra X-ray Observatory is the third in NASA's family of "Great Observatories." The Chandra X-ray Observatory, launched by Space Shuttle Columbia on July 23, 1999, is NASA's newest Great Observatory. The Chandra space flight software is the operational software, which controls and directs the Chandra X-ray Observatory. The Chandra flight software has executed faultlessly for over 13,000 hours on-orbit. The Chandra flight software directly controls the Pointing, Aspect Determination, Electrical Power Subsystem, Propulsion system, and the Command, Communications, and Data Management subsystems. The software controls the spacecraft operations during all phases of the mission. The software also performs thermal control of the telescope to maintain pointing accuracy and monitors radiation levels throughout the orbit so that the Science Instruments can be safed if radiation thresholds are exceeded. The efficient operation of Chandra flight software has enabled the gathering of crucial science data. The Chandra flight software fault protection is the key to early detection and prevention of science instrument or spacecraft damage in an operating platform/environment, which is completely unforgiving. Permanently open Sun Shade Door and ACIS focal plane radiator sensitivity exposes science instruments and mirrors to damage for pointing anomalies causing an attitude excursion. The Chandra flight software must prevent these attitude excursions from occurring for ANY failure. Another example is that the power system has an unregulated bus, which imposes severe operating requirements on Chandra flight software to control array pointing and battery connection/disconnect using a unique algorithmic and logic approach. The Chandra flight software has enabled a truly autonomous vehicle with greater than 99% of all mission data collected as planned. Less than 15% of spacecraft operations are conducted in view (1

  17. On the X-Ray Low- and High-Velocity Outflows in Active Galactic Nuclei

    NASA Technical Reports Server (NTRS)

    Ramirez, J. M.; Tombesi, F.

    2012-01-01

    An exploration of the relationship between bolometric luminosity and outflow velocity for two classes of X-ray outflows in a large sample of active galactic nuclei has been performed. We find that line radiation pressure could be one physical mechanism that might accelerate the gas we observe in warm absorber, v approx. 100-1000 km/s, and on comparable but less stringent grounds the ultrafast outflows, v approx. 0.03-0.3c. If comparable with the escape velocity of the system, the first is naturally located at distances of the dusty torus, '" I pc, and the second at subparsec scales, approx.0.01 pc, in accordance with large set of observational evidence existing in the literature. The presentation of this relationship might give us key clues for our understanding of the different physical mechanisms acting in the centre of galaxies, the feedback process and its impact on the evolution of the host galaxy.

  18. X-RAY ACTIVITY PHASED WITH PLANET MOTION IN HD 189733?

    SciTech Connect

    Pillitteri, I.; Guenther, H. M.; Wolk, S. J.; Kashyap, V. L.; Cohen, O.

    2011-11-01

    We report on the follow-up XMM-Newton observation of the planet-hosting star HD 189733 we obtained in 2011 April. We observe a flare just after the secondary transit of the hot Jupiter. This event shares the same phase and many of the characteristics of the flare we observed in 2009. We suggest that a systematic interaction between planet and stellar magnetic fields when the planet passes close to active regions on the star can lead to periodic variability phased with planetary motion. By means of high-resolution X-ray spectroscopy with the Reflection Grating Spectrometer on board XMM-Newton, we determine that the corona of this star is unusually dense.

  19. In situ Raman and X-ray spectroscopies to monitor microbial activities under high hydrostatic pressure.

    PubMed

    Oger, Phil M; Daniel, Isabelle; Picard, Aude

    2010-02-01

    Until recently, monitoring of cells and cellular activities at high hydrostatic pressure (HHP) was mainly limited to ex situ observations. Samples were analyzed prior to and following the depressurization step to evaluate the effect of the pressure treatment. Such ex situ measurements have several drawbacks: (i) it does not allow for kinetic measurements and (ii) the depressurization step often leads to artifactual measurements. Here, we describe recent advances in diamond anvil cell (DAC) technology to adapt it to the monitoring of microbial processes in situ. The modified DAC is asymmetrical, with a single anvil and a diamond window to improve imaging quality and signal collection. Using this novel DAC combined to Raman and X-ray spectroscopy, we monitored the metabolism of glucose by baker's yeast and the reduction of selenite by Agrobacterium tumefaciens in situ under HHP. In situ spectroscopy is also a promising tool to study piezophilic microorganisms.

  20. A Search for Hard X-ray Emission from Active Stars Using CGRO/BATSE

    NASA Astrophysics Data System (ADS)

    White, S. M.; Harmon, B. A.; Lim, J.; Kundu, M. R.

    We report the results of a search for > 20 keV photons from active stars using CGRO/BATSE Earth-occultation observations. Twelve of the "usual suspects" together with 12 "placebo" locations have been analyzed using the BATSE software for occultation analysis developed at NASA/MSFC. There are four detections at the nominal 5sigma level, and eight at the 3sigma level. However the strongest detection (that of AB Dor) shows clear evidence for contamination from the nearby strong source LMC X-4. 18 of the 24 fields yield positive fluxes, indicating a clear bias in the results, and possibly indicating the presence of weak background hard X-ray sources detectable by BATSE in long-term studies.

  1. LoCuSS: A DYNAMICAL ANALYSIS OF X-RAY ACTIVE GALACTIC NUCLEI IN LOCAL CLUSTERS

    SciTech Connect

    Haines, C. P.; Pereira, M. J.; Egami, E.; Sanderson, A. J. R.; Smith, G. P.; Babul, A.; Edge, A. C.; Finoguenov, A.; Moran, S. M.; Okabe, N.

    2012-08-01

    We present a study of the distribution of X-ray active galactic nuclei (AGNs) in a representative sample of 26 massive clusters at 0.15 < z < 0.30, combining Chandra observations sensitive to X-ray point sources of luminosity L{sub X} {approx} 10{sup 42} erg s{sup -1} at the cluster redshift with extensive and highly complete spectroscopy of cluster members down to {approx}M*{sub K} + 2. In total we identify 48 X-ray AGNs among the cluster members, with luminosities 2 Multiplication-Sign 10{sup 41}-1 Multiplication-Sign 10{sup 44} erg s{sup -1}. Based on these identifications, we estimate that 0.73% {+-} 0.14% of cluster galaxies brighter than M{sub K} = -23.1 (M*{sub K} + 1.5) host an X-ray AGN with L{sub X} > 10{sup 42} erg s{sup -1}. In the stacked caustic diagram that shows (v{sub los} - (v))/{sigma}{sub v} versus r{sub proj}/r{sub 500}, the X-ray AGN appear to preferentially lie along the caustics, suggestive of an infalling population. They also appear to avoid the region with lowest cluster-centric radii and relative velocities (r{sub proj} < 0.4r{sub 500}; |v - (v)|/{sigma}{sub v} < 0.8), which is dominated by the virialized population of galaxies accreted earliest into the clusters. The line-of-sight velocity histogram of the X-ray AGN shows a relatively flat distribution, and is inconsistent with the Gaussian distribution expected for a virialized population at 98.9% confidence. Moreover, the velocity dispersion of the 48 X-ray AGNs is 1.51 times that of the overall cluster population, which is consistent with the {radical}2 ratio expected by simple energetic arguments when comparing infalling versus virialized populations. This kinematic segregation is significant at the 4.66{sigma} level. When splitting the X-ray AGN sample into two according to X-ray or infrared (IR) luminosity, both X-ray bright (L{sub X} > 10{sup 42}) and IR-bright (L{sub TIR} > 2 Multiplication-Sign 10{sup 10} L{sub Sun }) subsamples show higher velocity dispersions than their X-ray

  2. Closed bore XMR (CBXMR) systems for aortic valve replacement: Active magnetic shielding of x-ray tubes

    SciTech Connect

    Bracken, John A.; DeCrescenzo, Giovanni; Komljenovic, Philip; Lillaney, Prasheel V.; Fahrig, Rebecca; Rowlands, J. A.

    2009-05-15

    Hybrid closed bore x-ray/MRI systems are being developed to improve the safety and efficacy of percutaneous aortic valve replacement procedures by harnessing the complementary strengths of the x-ray and MRI modalities in a single interventional suite without requiring patient transfer between two rooms. These systems are composed of an x-ray C-arm in close proximity ({approx_equal}1 m) to an MRI scanner. The MRI magnetic fringe field can cause the electron beam in the x-ray tube to deflect. The deflection causes the x-ray field of view to shift position on the detector receptacle. This could result in unnecessary radiation exposure to the patient and the staff in the cardiac catheterization laboratory. Therefore, the electron beam deflection must be corrected. The authors developed an active magnetic shielding system that can correct for electron beam deflection to within an accuracy of 5% without truncating the field of view or increasing exposure to the patient. This system was able to automatically adjust to different field strengths as the external magnetic field acting on the x-ray tube was changed. Although a small torque was observed on the shielding coils of the active shielding system when they were placed in a magnetic field, this torque will not impact their performance if they are securely mounted on the x-ray tube and the C-arm. The heating of the coils of the shielding system for use in the clinic caused by electric current was found to be slow enough not to require a dedicated cooling system for one percutaneous aortic valve replacement procedure. However, a cooling system will be required if multiple procedures are performed in one session.

  3. VERY LARGE TELESCOPE/X-SHOOTER SPECTROSCOPY OF THE CANDIDATE BLACK HOLE X-RAY BINARY MAXI J1659-152 IN OUTBURST

    SciTech Connect

    Kaur, Ramanpreet; Kaper, Lex; Ellerbroek, Lucas E.; Russell, David M.; Altamirano, Diego; Wijnands, Rudy; Yang Yijung; Van der Horst, Alexander; Van der Klis, Michiel; D'Avanzo, Paolo; De Ugarte Postigo, Antonio; Fynbo, Johan P. U.; Flores, Hector; Goldoni, Paolo; Thoene, Christina C.; Kuulkers, Erik

    2012-02-20

    We present the optical to near-infrared spectrum of MAXI J1659-152 during the onset of its 2010 X-ray outburst. The spectrum was obtained with X-shooter on the ESO Very Large Telescope early in the outburst simultaneous with high-quality observations at both shorter and longer wavelengths. At the time of the observations, the source was in the low-hard state. The X-shooter spectrum includes many broad ({approx}2000 km s{sup -1}), double-peaked emission profiles of H, He I, and He II, characteristic signatures of a low-mass X-ray binary during outburst. We detect no spectral signatures of the low-mass companion star. The strength of the diffuse interstellar bands results in a lower limit to the total interstellar extinction of A{sub V} {approx_equal} 0.4 mag. Using the neutral hydrogen column density obtained from the X-ray spectrum we estimate A{sub V} {approx_equal} 1 mag. The radial velocity structure of the interstellar Na I D and Ca II H and K lines results in a lower limit to the distance of {approx}4 {+-} 1 kpc, consistent with previous estimates. With this distance and A{sub V} , the dereddened spectral energy distribution represents a flat disk spectrum. The two 10 minute X-shooter spectra show significant variability in the red wing of the emission-line profiles, indicating a global change in the density structure of the disk, though on a timescale much shorter than the typical viscous timescale of the disk.

  4. Point spread function and centroiding accuracy measurements with the JET-X mirror and MOS CCD detector of the Swift gamma ray burst explorer's X-ray telescope

    NASA Astrophysics Data System (ADS)

    Ambrosi, R. M.; Abbey, A. F.; Hutchinson, I. B.; Willingale, R.; Wells, A.; Short, A. D. T.; Campana, S.; Citterio, O.; Tagliaferri, G.; Burkert, W.; Brauninger, H.

    2002-08-01

    The optical components of the Swift X-ray telescope (XRT) are already developed items. They are the flight spare X-ray mirror from the JET-X/Spectrum-X program and an MOS CCD (CCD22) of the type currently operating in orbit as part of the EPIC focal plane camera on XMM-Newton (SPIE 4140 (2000) 64). The JET-X mirrors were first calibrated at the Max Plank Institute for Extraterrestrial Physics' (MPE) Panter facility, Garching, Germany in 1996 (SPIE 2805 (1996) 56; SPIE 3114 (1997) 392). Half-energy widths of 16arcsec at 1.5keV were confirmed for the two flight mirrors and the flight spare. The calibration of the flight spare was repeated at Panter in July 2000 in order to establish whether any changes had occurred during the 4yr that the mirror had been in storage at the OAB, Milan, Italy. The results reported in this paper confirm that the resolution of the JET-X mirrors has remained stable over this storage period. In an extension of this test program, the flight spare EPIC camera was installed at the focus of the JET-X mirror to simulate the optical system of the Swift XRT. Tolerances in the mirror focal length, the on-axis and off-axis point spread functions were measured and calibration data sets were used to obtain centroid positions of X-ray point sources. The results confirmed Swift's ability to determine the centroid positions of sources at 100mCrab brightness to better than 1arcsec and provided a calibration of the centroiding process as a function of source flux and off-axis angle. The presence of background events in the image frame introduced errors in the centroiding process and this was accounted for by reducing the sampling area used for the centroiding algorithm.

  5. SWIFT X-RAY TELESCOPE TIMING OBSERVATIONS OF THE BLACK HOLE BINARY SWIFT J1753.5-0127: DISK-DILUTED FLUCTUATIONS IN THE OUTBURST PEAK

    SciTech Connect

    Kalamkar, M.; Van der Klis, M.; Uttley, P.; Altamirano, Diego; Wijnands, Rudy

    2013-04-01

    After a careful analysis of the instrumental effects on the Poisson noise to demonstrate the feasibility of detailed stochastic variability studies with the Swift X-Ray Telescope (XRT), we analyze the variability of the black hole X-ray binary SWIFT J1753.5-0127 in all XRT observations during 2005-2010. We present the evolution of the power spectral components along the outburst in two energy bands: soft (0.5-2 keV) and hard (2-10 keV), and in the hard band we find results consistent with those from the Rossi X-Ray Timing Explorer (RXTE). The advantage of the XRT is that we can also explore the soft band not covered by RXTE. The source has previously been suggested to host an accretion disk extending down to close to the black hole in the low hard state, and to show low-frequency variability in the soft-band intrinsic to this disk. Our results are consistent with this, with stronger low-frequency variability at low intensities in the soft than in the hard band. From our analysis, we are able to present the first measurements of the soft-band variability in the peak of the outburst. We find the soft band to be less variable than the hard band, especially at high frequencies, opposite to what is seen at low intensity. Both results can be explained within the framework of a simple two emission-region model where the hot flow is more variable in the peak of the outburst and the disk is more variable at low intensities.

  6. The Hard X-Ray Sky: Recent Observational Progress

    NASA Technical Reports Server (NTRS)

    Gehrels, Neil; Cannizzo, John K.

    2010-01-01

    The last fifty years have witnessed the birth, development, and maturation to full potential of hard X-ray astrophysics. The primary force driving the history of the field has been the development of space-based instrumentation optimized for getting the maximum science out of observations of high-energy photons from astrophysical sources. Hard X-ray telescopes are leading research in areas such as galactic diffuse emission, galactic transients, and active galactic nuclei.

  7. The Hard X-ray Sky: Recent Observational Progress

    SciTech Connect

    Gehrels, Neil

    2009-05-11

    The last fifty years have witnessed the birth, development, and maturation to full potential of hard X-ray astrophysics. The primary force driving the history of the field has been the development of space-based instrumentation optimized for getting the maximum science out of observations of high-energy photons from astrophysical sources. Hard X-ray telescopes are leading research in areas such as galactic diffuse emission, galactic transients, and active galactic nuclei.

  8. Discovery of Radio Pulsations from the X-ray Pulsar JO205+6449 in Supernova Remnant 3C58 with the Green Bank Telescope

    NASA Technical Reports Server (NTRS)

    Camilo, F.; Stairs, I. H.; Lorimer, D. R.; Backer, D. C.; Ransom, S. M.; Klein, B.; Wielebinski, R.; Kramer, M.; McLaughlin, M. A.; Arzoumanian, Z.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We report the discovery with the 100m Green Bank Telescope of 65 ms radio pulsations from the X-ray pulsar J0205+6449 at the center of supernova remnant 3C58, making this possibly the youngest radio pulsar known. From our observations at frequencies of 820 and 1375 MHz, the free electron column density to USSR J0205+6449 is found to be 140.7 +/- 0.3/cc pc. The barycentric pulsar period P and P(dot) determined from a phase-coherent timing solution are consistent with the values previously measured from X-ray observations. The averaged radio profile of USSR J0205+6449 consists of one sharp pulse of width = 3 ms = 0.05 P. The pulsar is an exceedingly weak radio source, with pulse-averaged flux density in the 1400 MHz band of approximately 45 micro-Jy and a spectral index of approximately -2.1. Its radio luminosity of approximately 0.5 may kpc(exp 2) at 1400 MHz is lower than that of approximately 99% of known pulsar and is the lowest among known young pulsars.

  9. Nanoimaging granule dynamics and subcellular structures in activated mast cells using soft X-ray tomography

    PubMed Central

    Chen, Huan-Yuan; Chiang, Dapi Meng-Lin; Lin, Zi-Jing; Hsieh, Chia-Chun; Yin, Gung-Chian; Weng, I.-Chun; Guttermann, Peter; Werner, Stephan; Henzler, Katja; Schneider, Gerd; Lai, Lee-Jene; Liu, Fu-Tong

    2016-01-01

    Mast cells play an important role in allergic responses. During activation, these cells undergo degranulation, a process by which various kinds of mediators stored in the granules are released. Granule homeostasis in mast cells has mainly been studied by electron microscopy (EM), where the fine structures of subcellular organelles are partially destroyed during sample preparation. Migration and fusion of granules have not been studied in detail in three dimensions (3D) in unmodified samples. Here, we utilized soft X-ray tomography (SXT) coupled with fluorescence microscopy to study the detailed structures of organelles during mast cell activation. We observed granule fission, granule fusion to plasma membranes, and small vesicles budding from granules. We also detected lipid droplets, which became larger and more numerous as mast cells were activated. We observed dramatic morphological changes of mitochondria in activated mast cells and 3D-reconstruction revealed the highly folded cristae inner membrane, features of functionally active mitochondria. We also observed giant vesicles containing granules, mitochondria, and lipid droplets, which we designated as granule-containing vesicles (GCVs) and verified their presence by EM in samples prepared by cryo-substitution, albeit with a less clear morphology. Thus, our studies using SXT provide significant insights into mast cell activation at the organelle level. PMID:27748356

  10. Probing the Masses and Radii of Donor Stars in Eclipsing X-Ray Binaries with the Swift Burst Alert Telescope

    NASA Astrophysics Data System (ADS)

    Coley, Joel B.; Corbet, Robin H. D.; Krimm, Hans A.

    2015-08-01

    Physical parameters of both the mass donor and compact object can be constrained in X-ray binaries with well-defined eclipses, as our survey of wind-fed supergiant X-ray binaries IGR J16393-4643, IGR J16418-4532, IGR J16479-4514, IGR J18027-2016, and XTE J1855-026 reveals. Using the orbital period and Kepler’s third law, we express the eclipse half-angle in terms of radius, inclination angle, and the sum of the masses. Pulse-timing and radial velocity curves can give masses of both the donor and compact object as in the case of the “double-lined” binaries IGR J18027-2016 and XTE J1855-026. The eclipse half angles are {15}-2+3, {31.7}-0.8+0.7, 32 ± 2,34 ± 2, and 33.6+/- 0.7 degrees for IGR J16393-4643, IGR J16418-4532, IGR J16479-4514, IGR J18027-2016, and XTE 1855-026, respectively. In wind-fed systems, the primary not exceeding the Roche-lobe size provides an upper limit on system parameters. In IGR J16393-4643, spectral types of B0 V or B0-5 III are found to be consistent with the eclipse duration and Roche-lobe, but the previously proposed donor stars in IGR J16418-4532 and IGR J16479-4514 were found to be inconsistent with the Roche-lobe size. Stars with spectral types O7.5 I and earlier are possible. For IGR J18027-2016, the mass and radius of the donor star lie between 18.6-19.4 {M}⊙ and 17.4-19.5 {R}⊙ . We constrain the neutron star mass between 1.37 and 1.43 {M}⊙ .We find the mass and radius of the donor star in XTE J1855-026 to lie between 19.6-20.2 {M}⊙ and 21.5-23.0 {R}⊙ . The neutron star mass was constrained to 1.77-1.82 {M}⊙ . Eclipse profiles are asymmetric in IGR J18027-2016 and XTE J1855-026, which we attribute to accretion wakes.

  11. X-ray structure and activities of an essential Mononegavirales L-protein domain

    PubMed Central

    Paesen, Guido C.; Collet, Axelle; Sallamand, Corinne; Debart, Françoise; Vasseur, Jean-Jacques; Canard, Bruno; Decroly, Etienne; Grimes, Jonathan M.

    2015-01-01

    The L protein of mononegaviruses harbours all catalytic activities for genome replication and transcription. It contains six conserved domains (CR-I to -VI; Fig. 1a). CR-III has been linked to polymerase and polyadenylation activity, CR-V to mRNA capping and CR-VI to cap methylation. However, how these activities are choreographed is poorly understood. Here we present the 2.2-Å X-ray structure and activities of CR-VI+, a portion of human Metapneumovirus L consisting of CR-VI and the poorly conserved region at its C terminus, the +domain. The CR-VI domain has a methyltransferase fold, which besides the typical S-adenosylmethionine-binding site (SAMP) also contains a novel pocket (NSP) that can accommodate a nucleoside. CR-VI lacks an obvious cap-binding site, and the SAMP-adjoining site holding the nucleotides undergoing methylation (SUBP) is unusually narrow because of the overhanging +domain. CR-VI+ sequentially methylates caps at their 2′O and N7 positions, and also displays nucleotide triphosphatase activity. PMID:26549102

  12. Small-angle neutron and X-ray scattering reveal conformational changes in rhodopsin activation

    NASA Astrophysics Data System (ADS)

    Shrestha, Utsab R.; Bhowmik, Debsindhu; Perera, Suchitrhanga M. C. D.; Chawla, Udeep; Struts, Andrey V.; Graziono, Vito; Pingali, Sai Venkatesh; Heller, William T.; Qian, Shuo; Brown, Michael F.; Chu, Xiang-Qiang

    2015-03-01

    Understanding G-protein-coupled receptor (GPCR) activation plays a crucial role in the development of novel improved molecular drugs. During photo-activation, the retinal chromophore of the visual GPCR rhodopsin isomerizes from 11-cis to all-trans conformation, yielding an equilibrium between inactive Meta-I and active Meta-II states. The principal goals of this work are to address whether the activation of rhodopsin leads to a single state or a conformational ensemble, and how protein organizational structure changes with detergent environment in solution. We use both small-angle neutron scattering (SANS) and small-angle X-ray scattering (SAXS) techniques to answer the above questions. For the first time we observe the change in protein conformational ensemble upon photo-activation by SANS with contrast variation, which enables the separate study of the protein structure within the detergent assembly. In addition, SAXS study of protein structure within detergent assembly suggests that the detergent molecules form a belt of monolayer (micelle) around protein with different geometrical shapes to keep the protein in folded state.

  13. Shedding Light on the Compton-thick Active Galactic Nucleus in the Ultraluminous Infrared Galaxy UGC 5101 with Broadband X-Ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Oda, Saeko; Tanimoto, Atsushi; Ueda, Yoshihiro; Imanishi, Masatoshi; Terashima, Yuichi; Ricci, Claudio

    2017-02-01

    We report the broadband X-ray spectra of the ultraluminous infrared galaxy (ULIRG) UGC 5101 in the 0.25–100 keV band observed with the Swift/Burst Alert Telescope (BAT), Nuclear Spectroscopic Telescope Array (NuSTAR), Suzaku, XMM-Newton, and Chandra. A Compton-thick active galactic nucleus (AGN) obscured with a hydrogen column density of ≈ 1.3× {10}24 cm‑2 is detected above 10 keV. A spectral fit with a numerical torus model favors a large half-opening angle of the torus, > 41°, suggesting that the covering fraction of material heavily obscuring the X-ray source is moderate. The intrinsic 2–10 keV luminosity is determined to be ≈ 1.4× {10}43 erg s‑1, which is ≈ 2.5 times larger than the previous estimate using only data below 10 keV with a simple spectral model. We find that UGC 5101 shows the ratio between the [O iv] 26 μm line and 2–10 keV luminosities similar to those of normal Seyfert galaxies, along with other ULIRGs observed with NuSTAR, indicating that a significant portion of local ULIRGs are not really “X-ray faint” with respect to the flux of forbidden lines originating from the narrow-line region. We propose a possible scenario that (1) the AGN in UGC 5101 is surrounded not only by Compton-thick matter located close to the equatorial plane but also by Compton-thin ({N}{{H}}∼ {10}21 cm‑2) matter in the torus-hole region and (2) it is accreting at a high Eddington rate with a steep UV to X-ray spectral energy distribution. Nevertheless, we argue that AGNs in many ULIRGs do not look extraordinary (i.e., extremely X-ray faint), as suggested by recent works, compared with normal Seyferts.

  14. The X-ray luminosity function of active galactic nuclei in the redshift interval z=3-5

    NASA Astrophysics Data System (ADS)

    Georgakakis, A.; Aird, J.; Buchner, J.; Salvato, M.; Menzel, M.-L.; Brandt, W. N.; McGreer, I. D.; Dwelly, T.; Mountrichas, G.; Koki, C.; Georgantopoulos, I.; Hsu, L.-T.; Merloni, A.; Liu, Z.; Nandra, K.; Ross, N. P.

    2015-10-01

    We combine deep X-ray survey data from the Chandra observatory and the wide-area/shallow XMM-XXL field to estimate the active galactic nuclei (AGN) X-ray luminosity function in the redshift range z = 3-5. The sample consists of nearly 340 sources with either photometric (212) or spectroscopic (128) redshift in the above range. The combination of deep and shallow survey fields also provides a luminosity baseline of three orders of magnitude, LX(2-10 keV) ≈ 1043-1046 erg s- 1 at z > 3. We follow a Bayesian approach to determine the binned AGN space density and explore their evolution in a model-independent way. Our methodology properly accounts for Poisson errors in the determination of X-ray fluxes and uncertainties in photometric redshift estimates. We demonstrate that the latter is essential for unbiased measurement of space densities. We find that the AGN X-ray luminosity function evolves strongly between the redshift intervals z = 3-4 and z = 4-5. There is also suggestive evidence that the amplitude of this evolution is luminosity dependent. The space density of AGN with LX(2-10 keV) < 1045 erg s- 1 drops by a factor of 5 between the redshift intervals above, while the evolution of brighter AGN appears to be milder. Comparison of our X-ray luminosity function with that of ultraviolet (UV)/optical selected quasi-stellar objects at similar redshifts shows broad agreement at bright luminosities, LX(2-10 keV) > 1045 erg s- 1. At fainter luminosities X-ray surveys measure higher AGN space densities. The faint-end slope of UV/optical luminosity functions, however, is steeper than for X-ray selected AGN. This implies that the Type I AGN fraction increases with decreasing luminosity at z > 3, opposite to trends established at lower redshift. We also assess the significance of AGN in keeping the hydrogen ionized at high redshift. Our X-ray luminosity function yields ionizing photon rate densities that are insufficient to keep the Universe ionized at redshift z > 4. A

  15. NuSTAR Observations of the Compton-thick Active Galactic Nucleus and Ultraluminous X-Ray Source Candidate in NGC 5643

    NASA Astrophysics Data System (ADS)

    Annuar, A.; Gandhi, P.; Alexander, D. M.; Lansbury, G. B.; Arévalo, P.; Ballantyne, D. R.; Baloković, M.; Bauer, F. E.; Boggs, S. E.; Brandt, W. N.; Brightman, M.; Christensen, F. E.; Craig, W. W.; Del Moro, A.; Hailey, C. J.; Harrison, F. A.; Hickox, R. C.; Matt, G.; Puccetti, S.; Ricci, C.; Rigby, J. R.; Stern, D.; Walton, D. J.; Zappacosta, L.; Zhang, W.

    2015-12-01

    We present two Nuclear Spectroscopic Telescope Array (NuSTAR) observations of the local Seyfert 2 active galactic nucleus (AGN) and an ultraluminous X-ray source (ULX) candidate in NGC 5643. Together with archival data from Chandra, XMM-Newton, and Swift-BAT, we perform a high-quality broadband spectral analysis of the AGN over two decades in energy (˜0.5-100 keV). Previous X-ray observations suggested that the AGN is obscured by a Compton-thick (CT) column of obscuring gas along our line of sight. However, the lack of high-quality ≳10 keV observations, together with the presence of a nearby X-ray luminous source, NGC 5643 X-1, have left significant uncertainties in the characterization of the nuclear spectrum. NuSTAR now enables the AGN and NGC 5643 X-1 to be separately resolved above 10 keV for the first time and allows a direct measurement of the absorbing column density toward the nucleus. The new data show that the nucleus is indeed obscured by a CT column of NH ≳ 5 × 1024 cm-2. The range of 2-10 keV absorption-corrected luminosity inferred from the best-fitting models is L2-10,int = (0.8-1.7) × 1042 erg s-1, consistent with that predicted from multiwavelength intrinsic luminosity indicators. In addition, we also study the NuSTAR data for NGC 5643 X-1 and show that it exhibits evidence of a spectral cutoff at energy E ˜ 10 keV, similar to that seen in other ULXs observed by NuSTAR. Along with the evidence for significant X-ray luminosity variations in the 3-8 keV band from 2003 to 2014, our results further strengthen the ULX classification of NGC 5643 X-1.

  16. Beyond Chandra - the X-ray Surveyor

    NASA Technical Reports Server (NTRS)

    Weisskopf, Martin C.; Gaskin, Jessica A.; Tananbaum, Harvey; Vhiklinin, Alexey

    2015-01-01

    Over the past 16 years, NASA's Chandra X-ray Observatory has provided an unparalleled means for exploring the high energy universe with its half-arcsecond angular resolution. Chandra studies have deepened our understanding of galaxy clusters, active galactic nuclei, galaxies, supernova remnants, planets, and solar system objects addressing most, if not all, areas of current interest in astronomy and astrophysics. As we look beyond Chandra, it is clear that comparable or even better angular resolution with greatly increased photon throughput is essential to address even more demanding science questions, such as the formation and subsequent growth of black hole seeds at very high redshift; the emergence of the first galaxy groups; and details of feedback over a large range of scales from galaxies to galaxy clusters. Recently, NASA Marshall Space Flight Center, together with the Smithsonian Astrophysical Observatory, has initiated a concept study for such a mission now named the X-ray Surveyor. This concept study starts with a baseline payload consisting of a high resolution X-ray telescope and an instrument set which may include an X-ray calorimeter, a wide-field imager and a dispersive grating spectrometer and readout. The telescope would consist of highly nested thin shells, for which a number of technical approaches are currently under development, including adjustable X-ray optics, differential deposition, and modern polishing techniques applied to a variety of substrates. In many areas, the mission requirements would be no more stringent than those of Chandra, and the study takes advantage of similar studies for other large area missions carried out over the past two decades. Initial assessments indicate that such an X-ray mission is scientifically compelling, technically feasible, and worthy of a high prioritization by the next American National Academy of Sciences Decadal Survey for Astronomy and Astrophysics.

  17. Imaging Molecular Signatures of Breast Cancer With X-ray Activated Nano-Phosphors

    DTIC Science & Technology

    2011-09-01

    europium (red) were studied. The light emission was imaged in a clinical X-ray scanner with a cooled CCD camera and a spectrophotometer; dose...to the CCD camera in the chosen imaging geometry was measured at less than 0.02cGy/sec. Emitted light was found to be linear with dose (R2 = 1) and...x-ray scanner with a cooled CCD camera and a spectrophotometer; dose measurements were determined with a calibrated dosimeter. Using these properties

  18. The Chandra X-Ray Observatory

    NASA Technical Reports Server (NTRS)

    Weisskopf, Martin C.

    2013-01-01

    The Chandra X-ray Observatory, the third of NASA's four Great Observatories and its flagship mission for X-ray astronomy, was launched by NASA's Space Shuttle Columbia on July 23, 1999. The first X-ray sources were observed on August 12, 1999. The brightest of these sources named Leon X-1 in honor of Chandra's Telescope Scientist who played the leading role in establishing the key to Chandra's great advance in angular resolution. Over the past years, the Observatory's ability to provide sub-arc second X-ray images and high resolution spectra has established it as one of the most versatile and powerful tools for astrophysical research in the 21st century. Chandra explores the high-energy regions of the universe, observing X-ray sources with fluxes ranging over more than 10 orders of magnitude. The longevity of Chandra also provides a long observing baseline enabling temporal studies over time-scales of years. I will discuss how the Observatory works, the current operational status, and scientific highlights covering a variety of objects from stars with nearby planets that impact the stellar activity to the deepest Chandra surveys.

  19. Long-term Optical Activity of the Hard X-ray Flaring Star DG CVn

    NASA Astrophysics Data System (ADS)

    Šimon, V.

    2017-04-01

    DG CVn is a young late-type star which displayed an X-ray and optical superflare in 2014. This paper presents an analysis of the long-term activity of this object in the optical band. I used the photographic data from DASCH (Digital Access to a Sky Century @ Harvard). These measurements from the years 1895-1989 cover the blue spectral region. CCD V-band ASAS data were used for several UV Cet-type stars to place the activity of DG CVn in the context of flaring stars. I show that three large brightenings (flares) of DG CVn by more than 1 mag were detected on the DASCH plates. The character of the long-term activity (regarding the histogram of brightness) of DG CVn is compatible with those of flaring stars UV Cet and V371 Ori. The flares brighter than ˜ 0.4 mag represent less than 1 percent of the observed data in all three objects

  20. Caliste 64: detection unit of a spectro imager array for a hard x-ray space telescope

    NASA Astrophysics Data System (ADS)

    Meuris, A.; Limousin, O.; Lugiez, F.; Gevin, O.; Pinsard, F.; Blondel, C.; Le Mer, I.; Delagnes, E.; Vassal, M. C.; Soufflet, F.; Bocage, R.

    2008-07-01

    In the frame of the hard X-ray Simbol-X observatory, a joint CNES-ASI space mission to be flown in 2014, a prototype of miniature Cd(Zn)Te camera equipped with 64 pixels has been designed. The device, called Caliste 64, is a spectro-imager with high resolution event time-tagging capability. Caliste 64 integrates a Cd(Zn)Te semiconductor detector with segmented electrode and its front-end electronics made of 64 independent analog readout channels. This 1 × 1 × 2 cm3 camera, able to detect photons in the range from 2 keV up to 250 keV, is an elementary detection unit juxtaposable on its four sides. Consequently, large detector array can be made assembling a mosaic of Caliste 64 units. Electronics readout module is achieved by stacking four IDeF-X V1.1 ASICs, perpendicular to the detection plane. We achieved good noise performances, with a mean Equivalent Noise Charge of ~65 electrons rms over the 64 channels. Time resolution is better than 70 ns rms for energy deposits greater than 50 keV, taking into account electronic noise and technological dispersal, which enables to reject background by anticoincidence with very low probability of error. For the first prototypes, we chose CdTe detectors equipped with Al-Ti-Au Schottky barrier contacts because of their very low dark current and excellent spectroscopic performances. So far, three Caliste 64 cameras have been realized and tested. When the crystal is cooled down to -10°C, the sum spectrum built with the 64 pixels of a Caliste 64 sample results in a spectral resolution of 664 eV FWHM at 13.94 keV and 841 eV FWHM at 59.54 keV.

  1. X-ray microtomography shows pore structure and tortuosity in alkali-activated binders

    SciTech Connect

    Provis, John L.; Myers, Rupert J.; White, Claire E.; Rose, Volker; Deventer, Jannie S.J. van

    2012-06-15

    Durability of alkali-activated binders is of vital importance in their commercial application, and depends strongly on microstructure and pore network characteristics. X-ray microtomography ({mu}CT) offers, for the first time, direct insight into microstructural and pore structure characteristics in three dimensions. Here, {mu}CT is performed on a set of sodium metasilicate-activated fly ash/slag blends, using a synchrotron beamline instrument. Segmentation of the samples into pore and solid regions is then conducted, and pore tortuosity is calculated by a random walker method. Segmented porosity and diffusion tortuosity are correlated, and vary as a function of slag content (slag addition reduces porosity and increases tortuosity), and sample age (extended curing gives lower porosity and higher tortuosity). This is particularly notable for samples with {>=} 50% slag content, where a space-filling calcium (alumino)silicate hydrate gel provides porosity reductions which are not observed for the sodium aluminosilicate ('geopolymer') gels which do not chemically bind water of hydration.

  2. X-ray structures of AMPA receptor-cone snail toxin complexes illuminate activation mechanism.

    PubMed

    Chen, Lei; Dürr, Katharina L; Gouaux, Eric

    2014-08-29

    AMPA-sensitive glutamate receptors are crucial to the structural and dynamic properties of the brain, to the development and function of the central nervous system, and to the treatment of neurological conditions from depression to cognitive impairment. However, the molecular principles underlying AMPA receptor activation have remained elusive. We determined multiple x-ray crystal structures of the GluA2 AMPA receptor in complex with a Conus striatus cone snail toxin, a positive allosteric modulator, and orthosteric agonists, at 3.8 to 4.1 angstrom resolution. We show how the toxin acts like a straightjacket on the ligand-binding domain (LBD) "gating ring," restraining the domains via both intra- and interdimer cross-links such that agonist-induced closure of the LBD "clamshells" is transduced into an irislike expansion of the gating ring. By structural analysis of activation-enhancing mutants, we show how the expansion of the LBD gating ring results in pulling forces on the M3 helices that, in turn, are coupled to ion channel gating.

  3. CAN WE REPRODUCE THE X-RAY BACKGROUND SPECTRAL SHAPE USING LOCAL ACTIVE GALACTIC NUCLEI?

    SciTech Connect

    Vasudevan, Ranjan V.; Mushotzky, Richard F.; Gandhi, Poshak

    2013-06-20

    The X-ray background (XRB) is due to the aggregate of active galactic nuclei (AGNs), which peak in activity at z {approx} 1 and is often modeled as the sum of different proportions of unabsorbed, moderately, and heavily absorbed AGN. We present the summed spectrum of a complete sample of local AGN (the Northern Galactic Cap of the 58 month Swift/BAT catalog, z < 0.2) using 0.4-200 keV data and directly determine the different proportions of unabsorbed, moderately and heavily absorbed AGN that make up the summed spectrum. This stacked low redshift AGN spectrum is remarkably similar in shape to the XRB spectrum (when shifted to z {approx} 1), but the observed proportions of different absorption populations differ from most XRB synthesis models. AGN with Compton-thick absorption account for only {approx}12% of the sample, but produce a significant contribution to the overall spectrum. We confirm that Compton reflection is more prominent in moderately absorbed AGN and that the photon index differs intrinsically between unabsorbed and absorbed AGN. The AGN in our sample account for only {approx}1% of the XRB intensity. The reproduction of the XRB spectral shape suggests that strong evolution in individual AGN properties is not required between z {approx} 0 and 1.

  4. Synthesis, spectroscopic structure identification, X-ray study and anticancer activities of new angularly fused quinobenzothiazines

    NASA Astrophysics Data System (ADS)

    Pluta, K.; Szmielew, M.; Suwińska, K.; Latocha, M.

    2016-10-01

    Synthesis of 16 new tetracyclic angularly fused azaphenothiazines, 8-, 9- and 10-substituted quinobenzo-1,4-thiazines (benzo[a]-3-azaphenothiazines) was based on the reactions of dichlorodiquinolinyl disulfide and diquinodithiin with substituted anilines. Whereas the reactions with p-fluoroaniline and p-methylthioaniline led to only one product, the reaction with m-triflouromethylaniline led to isomeric compounds. The obtained 8-10-substituted 12H-quinobenzothiazines were further transformed into 12-substituted derivatives through alkylation of the thiazine nitrogen atom. The structure analysis was based on 1D and 2D NMR (NOESY, COSY, HSQC and HMBC) spectra which enabled to distinguish the isomers and to exclude retro-Smiles rearrangement and the azine nitrogen atom alkylation pathways. This supposition was fully confirmed by X-ray analysis showing the quinobenzothiazine system to be folded and the substituent at the thiazine nitrogen atom in an equatorial position. Some compounds exhibited anticancer activity against MCF-7, MDA-MB-231 and SNB-19 cell lines similar to a reference drug cisplatin. The structure-activity relationship of the compounds were discussed.

  5. Synthesis, X-ray crystal structure, antimicrobial activity and photodynamic effects of some thiabendazole complexes.

    PubMed

    Mothilal, K K; Karunakaran, Chandran; Rajendran, Ayyapan; Murugesan, Ramachandran

    2004-02-01

    An interesting series of metal complexes of thiabendazole (tbz) is synthesized and characterized by elemental analyses and spectroscopic studies. The crystal structure of the hydrogen bonded one dimensional Co(II) complex, namely [Co(tbz)(2)(NO(3))(H(2)O)](NO(3)) is solved by single crystal X-ray diffraction. The complex crystallizes in monoclinic space group P2(1)/a with unit cell parameters, a=14.366(2), b=11.459(4), c=15.942(3) A, beta=113.78(3) degrees and z=4. The unit cell packing reveals an extensive hydrogen bonding involving a water molecule, nitrate ligands and the protonated nitrogen atoms of the tbz ligands, resulting in a one dimensional hydrogen bonding pattern. The antimicrobial activity of the complexes against selected bacteria (Escherichia coli and Bacillus subtilis) and yeast (Aspergillus flavues) is estimated. The relationship between the enzymatic production of ROS and antimicrobial activity of the complexes is examined, and a good correlation between two factors is found. Photodynamic quantum yields of singlet oxygen production (RNO bleaching assay) and rate of superoxide generation (SOD inhibitable ferricytochrome c reduction assay and EPR spin trapping experiments using 5,5-dimethyl-1-pyrroline-N-oxide as spin trap) by the metal complexes have been studied.

  6. Theoretical modelling of X-ray fluorescence signals for different lunar compositions and dependence on solar activity

    NASA Astrophysics Data System (ADS)

    Banerjee, D.; Vadawale, S.

    2010-09-01

    We present a forward modelling technique for calculating the surface X-ray spectra for a variety of lunar terrains. Our calculations considered variations in solar fluxes from solar quiescent condition to large flare activity (M1 flare), and expected elemental concentrations in the target, as well as yield, instrumental, and viewing geometry parameters for X-ray induced fluorescence from the lunar surface. Additionally, we present estimates of anticipated XRF signals from prominent K α lines observable by a collimated 14 cm 2 X-ray detector from a 100 km lunar orbit with ˜20 km spatial resolution. Our results show that Mg, Al and Si characteristic K α lines can be observed for all solar conditions. The Ca K α lines line can be differentiated from a fixed background during more energetic solar conditions such as C1 and M1 flares, whereas Ti and Fe lines are identifiable only during C1 and M1 solar flare conditions for Apollo 12 site composition. Both the K α X-ray intensity ratios of Mg/Si and Al/Si correlate well with concentration ratios of Mg/Si and Al/Si, respectively, for B1 and M1 solar conditions. The K α X-ray intensity ratios of Fe/Si and Ca/Si correlates with concentration ratios of Fe/Si and Ca/Si, respectively, for M1 solar condition. In principle, the modelling technique outlined here can be used to determine absolute elemental abundances (Mg, Al, Si, Ca, Ti and Fe) from X-ray spectra measured during recent and future lunar missions.

  7. Exploring the Geometry of Circumnuclear Material in Active Galactic Nuclei through X-ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Rivers, Elizabeth

    I have studied the X-ray spectral properties of active galactic nuclei (AGN) in order to gain a better understanding of the nature of the circumnuclear material surrounding the central black hole in these objects. From the RXTE archive I constructed two survey samples of broad band X-ray spectra. The first was a bright sample of 23 AGN that had high quality spectra up to at least 100 keV, which provided constraints on the high energy rollover expected by models of inverse Comptonization of low energy photons. The average lower limit to Eroll was ˜225 keV for the majority of objects, implying a coronal electron temperature of kB Te ≳ 75 keV for these models. The second sample was an expanded survey of ˜100 AGN for which spectral parameters could be well-determined. I compared Fe line equivalent widths with measured Compton reflection hump strengths and found that on average ˜40% of the Fe line emission comes from reflection off Compton-thick material, with the remainder likely arising in isotropic emission from Compton-thin gas. In the full sample, the distributions of photon indices for Seyfert 1's and 2's were consistent with the idea that Seyferts share a common central engine, however the distributions of Compton reflection hump strengths did not support the classical picture of absorption by a torus and reflection off a Compton-thick disk with type depending only on inclination angle. I have concluded that a more complex reflecting geometry such as a combined disk and torus or clumpy torus is likely a more accurate picture of the Compton-thick material. I have performed additional analyses of individual objects. An occultation event in Cen A, discovered through RXTE monitoring, revealed the clumpy nature of its torus and placed constraints on the amount of material in the vicinity of the black hole in this object. A Suzaku long-look observation of MCG-2-58-22 provided constraints on the location of Fe line emitting material to ≳ 1200RS, likely associated

  8. Identification of 5 prime -adenylylimidodiphosphate-hydrolyzing enzyme activity in rabbit taste bud cells using X-ray microanalysis

    SciTech Connect

    Asanuma, N. )

    1990-01-01

    X-ray microanalysis has been used to characterize the enzyme activity hydrolyzing the ATP analogue 5'-adenylylimidodiphosphate (AMP-PNP) in taste bud cells. Rabbit foliate papillae fixed with paraformaldehyde and glutaraldehyde were incubated cytochemically with AMP-PNP as the substrate and lead ion as capture agent. The reaction product which appeared on the microvilli of taste bud cells was examined using an energy dispersive X-ray microanalyzer connected to an analytical electron microscope. The X-ray spectrum thus obtained was compared with that obtained from the product obtained from the demonstration of ATPase activity. Comparison of the phosphorus/lead ratios in the two products showed that twice as much phosphorus was released from an AMP-PNP molecule by the activity in question compared with that released from an ATP molecule by ATPase activity. This indicates that the enzyme hydrolyzes AMP-PNP into AMP and imidodiphosphate and that the enzyme is adenylate cyclase or ATP pyrophosphohydrolase, which possesses a similar hydrolytic property, but not ATPase or alkaline phosphatase, which hydrolyzes AMP-PNP into ADP-NH2 and orthophosphate. This paper provides an example of the use of X-ray microanalysis as a tool for enzyme distinction. The method is applicable to a variety of enzymes and tissues.

  9. X ray imaging microscope for cancer research

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.; Shealy, David L.; Brinkley, B. R.; Baker, Phillip C.; Barbee, Troy W., Jr.; Walker, Arthur B. C., Jr.

    1991-01-01

    The NASA technology employed during the Stanford MSFC LLNL Rocket X Ray Spectroheliograph flight established that doubly reflecting, normal incidence multilayer optics can be designed, fabricated, and used for high resolution x ray imaging of the Sun. Technology developed as part of the MSFC X Ray Microscope program, showed that high quality, high resolution multilayer x ray imaging microscopes are feasible. Using technology developed at Stanford University and at the DOE Lawrence Livermore National Laboratory (LLNL), Troy W. Barbee, Jr. has fabricated multilayer coatings with near theoretical reflectivities and perfect bandpass matching for a new rocket borne solar observatory, the Multi-Spectral Solar Telescope Array (MSSTA). Advanced Flow Polishing has provided multilayer mirror substrates with sub-angstrom (rms) smoothnesss for the astronomical x ray telescopes and x ray microscopes. The combination of these important technological advancements has paved the way for the development of a Water Window Imaging X Ray Microscope for cancer research.

  10. Hard-X-ray spectra of active galactic nuclei in the INTEGRAL complete sample

    NASA Astrophysics Data System (ADS)

    Molina, M.; Bassani, L.; Malizia, A.; Stephen, J. B.; Bird, A. J.; Bazzano, A.; Ubertini, P.

    2013-08-01

    In this paper, we present the hard-X-ray spectral analysis of a complete sample of active galactic nuclei (AGNs) detected by INTEGRAL/IBIS. In conjunction with IBIS spectra, we make use of Swift/BAT data, with the aim of cross-calibrating the two instruments, studying source variability and constraining some important spectral parameters. We find that flux variability is present in at least 14 per cent of the sample, while spectral variability is found only in one object. There is general good agreement between BAT and IBIS spectra, despite a systematic mismatch of about 22 per cent in normalization. When fitted with a simple power-law model, type 1 and type 2 sources appear to have very similar average photon indices, suggesting that they are powered by the same mechanism. As expected, we also find that a simple power law does not always describe the data sufficiently well, thus indicating a certain degree of spectral complexity, which can be ascribed to features like a high energy cut-off and/or a reflection component. Fixing the reflection to be 0, 1 or 2, we find that our sample covers quite a large range in photon indices as well as cut-off energies; however, the spread is due only to a small number of objects, while the majority of the AGNs lie within well-defined boundaries of photon index (1 ≤ Γ ≤ 2) and cut-off energy (30 ≤ Ecut ≤ 300 keV).

  11. X-ray absorption spectroscopic studies of the active sites of nickel- and copper-containing metalloproteins

    SciTech Connect

    Tan, G.O.

    1993-06-01

    X-ray absorption spectroscopy (XAS) is a useful tool for obtaining structural and chemical information about the active sites of metalloproteins and metalloenzymes. Information may be obtained from both the edge region and the extended X-ray absorption fine structure (EXAFS) or post-edge region of the K-edge X-ray absorption spectrum of a metal center in a compound. The edge contains information about the valence electronic structure of the atom that absorbs the X-rays. It is possible in some systems to infer the redox state of the metal atom in question, as well as the geometry and nature of ligands connected to it, from the features in the edge in a straightforward manner. The EXAFS modulations, being produced by the backscattering of the ejected photoelectron from the atoms surrounding the metal atom, provide, when analyzed, information about the number and type of neighbouring atoms, and the distances at which they occur. In this thesis, analysis of both the edge and EXAFS regions has been used to gain information about the active sites of various metalloproteins. The metalloproteins studied were plastocyanin (Pc), laccase and nickel carbon monoxide dehydrogenase (Ni CODH). Studies of Cu(I)-imidazole compounds, related to the protein hemocyanin, are also reported here.

  12. Understanding how active volcanoes work: a contribution from synchrotron X-ray computed microtomography

    NASA Astrophysics Data System (ADS)

    Polacci, M.; Baker, D. R.; Mancini, L.

    2009-04-01

    Volcanoes are complex systems that require the integration of many different geoscience disciplines to understand their behaviour and to monitor and forecast their activity. In the last two decades an increasing amount of information on volcanic processes has been obtained by studying the textures and compositions of volcanic rocks. Five years ago we started a continuing collaboration with the SYRMEP beamline of Elettra Sincrotrone, a third generation synchrotron light source near Trieste, Italy, with the goal of performing high-resolution, phase-contrast X-ray tomographic scans and reconstructing 3-D digital volumes of volcanic specimens. These volumes have been then used for the visualization of the internal structure of rocks and for the quantification of rock textures (i.e., vesicle and crystal volume fraction, individual vesicle volumes and shapes, vesicle connectivity, vesicle volume distributions, permeability simulations etc.). We performed tomographic experiments on volcanic products erupted from different hazardous volcanic systems in Italy and around the world: Campi Flegrei, Stromboli, Etna (Southern Italy), Villarrica (Chile), Yasur and Ambrym (Vanuatu Islands). As an example, we used the results of these studies to constrain the dynamics of vesiculation and degassing in basaltic (Polacci et al., 2006; Burton et al., 2007; Colò et al., 2007; Andronico et al., 2008; Polacci et al., 2008a) and trachytic (Piochi et al., 2008) magmas. A better knowledge of how gas is transported and lost from magmas has led us in turn to draw new implications on the eruptive style of these active, hazardous volcanoes (Polacci et al., 2008b). Work in progress consists of optimizing our procedure by establishing a precise protocol that will enable us to quantitatively study the 3-D texture and composition of rocks in a statistically representative way. Future work will concentrate on the study of the spatial relations between phases (crystals, vesicles and glass) in rocks

  13. THE LACK OF DIFFUSE, NON-THERMAL HARD X-RAY EMISSION IN THE COMA CLUSTER: THE SWIFT BURST ALERT TELESCOPE'S EYE VIEW

    SciTech Connect

    Wik, Daniel R.; Baumgartner, Wayne H.; Okajima, Takashi; Tueller, Jack; Finoguenov, Alexis; Mushotzky, Richard F.; Clarke, Tracy E.

    2011-02-01

    The Coma Cluster of galaxies hosts the brightest radio halo known and has therefore been the target of numerous searches for associated inverse Compton (IC) emission, particularly at hard X-ray energies where the IC signal must eventually dominate over thermal emission. The most recent search with the Suzaku Hard X-ray Detector failed to confirm previous IC detections with RXTE and BeppoSAX, instead setting an upper limit 2.5 times below their non-thermal flux. However, this discrepancy can be resolved if the IC emission is very extended, beyond the scale of the cluster radio halo. Using reconstructed sky images from the 58-month Swift Burst Alert Telescope (BAT) all-sky survey, the feasibility of such a solution is investigated. Building on Renaud et al., we test and implement a method for extracting the fluxes of extended sources, assuming specified spatial distributions. BAT spectra are jointly fit with an XMM-Newton EPIC-pn spectrum derived from mosaic observations. We find no evidence for large-scale IC emission at the level expected from the previously detected non-thermal fluxes. For all non-thermal spatial distributions considered, which span the gamut of physically reasonable IC models, we determine upper limits for which the largest (most conservative) limit is {approx}<4.2 x 10{sup -12} erg s{sup -1} cm{sup -2} (20-80 keV), which corresponds to a lower limit on the magnetic field B > 0.2 {mu} G. A nominal flux upper limit of <2.7 x 10{sup -12} erg s{sup -1} cm{sup -2}, with corresponding B > 0.25 {mu} G, is derived for the most probable IC distribution given the size of the radio halo and likely magnetic field radial profile.

  14. A Census of the Class of X-ray Active γ Cas Stars

    NASA Astrophysics Data System (ADS)

    Smith, M. A.; de Oliveira, R. L.; Motch, C.

    2016-11-01

    “γ Cas stars” are perhaps the primary contributors to the total hard X-ray flux from Galactic B stars. We review basic properties of 12 suspected or known members of this class. The sample extends out to 6-7 kpc and is finally sufficient to compare such basic properties as spectral type, rotation rate, binarity/Blue Straggler status, Hα lobe structure EWHα, Lx, temperature of the dominant X-ray emitting plasma component (kThot), and ranges in Lx and kThot.

  15. INSIGHT INTO ACTIVE GALACTIC NUCLEUS AND HOST GALAXY CO-EVOLUTION FROM HARD X-RAY EMISSION

    SciTech Connect

    Wang, J.; Zhou, X. L.; Wei, J. Y.

    2013-05-10

    We study the issue of active galactic nucleus (AGN) and host co-evolution by focusing on the correlation between the hard X-ray emission from central AGNs and the stellar populations of the host galaxies. Focusing on galaxies with strong H{alpha} line emission (EW(H{alpha}) > 5 A), both X-ray and optical spectral analyses are performed on 67 (partially) obscured AGNs that are selected from the XMM-Newton 2XMMi/SDSS-DR7 catalog originally cross-matched by Pineau et al. The sample allows us to study central AGN activity and host galaxy activity directly and simultaneously in individual objects. Combining the spectral analysis in both bands reveals that the older the stellar population of the host galaxy, the harder the X-ray emission will be, which was missed in our previous study where ROSAT hardness ratios were used. By excluding the contamination from host galaxies and from jet beaming emission, the correlation indicates that Compton cooling in the accretion disk corona decreases with the mean age of the stellar population. We argue that this correlation is related to the correlation of L/L{sub Edd} with the host stellar population. In addition, the [O I]/H{alpha} and [S II]/H{alpha} narrow-line ratios are identified to correlate with the spectral slope in hard X-rays, which can be inferred from the currently proposed evolution of the X-ray emission because of the confirmed tight correlations between the two line ratios and stellar population age.

  16. Planetary X-ray studies: past, present and future

    NASA Astrophysics Data System (ADS)

    Branduardi-Raymont, Graziella

    2016-07-01

    Our solar system is a fascinating physics laboratory and X-ray observations are now firmly established as a powerful diagnostic tool of the multiple processes taking place in it. The science that X-rays reveal encompasses solar, space plasma and planetary physics, and the response of bodies in the solar system to the impact of the Sun's activity. This talk will review what we know from past observations and what we expect to learn in the short, medium and long term. Observations with Chandra and XMM-Newton have demonstrated that the origin of Jupiter's bright soft X-ray aurorae lies in the Charge eXchange (CX) process, likely to involve the interaction with atmospheric neutrals of local magnetospheric ions, as well as those carried in the solar wind. At higher energies electron bremsstrahlung is thought to be the X-ray emitting mechanism, while the whole planetary disk acts as a mirror for the solar X-ray flux via Thomson and fluorescent scattering. This 'X-ray mirror' phenomenon is all that is observed from Saturn's disk, which otherwise lacks X-ray auroral features. The Earth's X-ray aurora is bright and variable and mostly due to electron bremsstrahlung and line emission from atmospheric species. Un-magnetised planets, Venus and Mars, do not show X-ray aurorae but display the interesting combination of mirroring the solar X-ray flux and producing X-rays by Solar Wind Charge eXchange (SWCX) in their exospheres. These processes respond to different solar stimulation (photons and solar wind plasma respectively) hence their relative contributions are seen to vary according to the Sun's output. Present and future of planetary X-ray studies are very bright. We are preparing for the arrival of the Juno mission at Jupiter this summer and for coordinated observations with Chandra and XMM-Newton on the approach and later during Juno's orbital phase. These will allow direct correlation of the local plasma conditions with the X-ray emissions and the establishment of the

  17. STRUCTURE AND MORPHOLOGY OF X-RAY-SELECTED ACTIVE GALACTIC NUCLEUS HOSTS AT 1 < z < 3 IN THE CANDELS-COSMOS FIELD

    SciTech Connect

    Fan, Lulu; Chen, Yang; Li, Jinrong; Lv, Xuanyi; Kong, Xu; Fang, Guanwen; Knudsen, Kirsten K.

    2014-03-20

    We analyze morphologies of the host galaxies of 35 X-ray-selected active galactic nuclei (AGNs) at z ∼ 2 in the Cosmic Evolution Survey field using Hubble Space Telescope/WFC3 imaging taken from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. We build a control sample of 350 galaxies in total by selecting 10 non-active galaxies drawn from the same field with a similar stellar mass and redshift for each AGN host. By performing two-dimensional fitting with GALFIT on the surface brightness profile, we find that the distribution of the Sérsic index (n) of AGN hosts does not show a statistical difference from that of the control sample. We measure the nonparametric morphological parameters (the asymmetry index A, the Gini coefficient G, the concentration index C, and the M {sub 20} index) based on point-source-subtracted images. All the distributions of these morphological parameters of AGN hosts are consistent with those of the control sample. We finally investigate the fraction of distorted morphologies in both samples by visual classification. Only ∼15% of the AGN hosts have highly distorted morphologies, possibly due to a major merger or interaction. We find there is no significant difference in the distortion fractions between the AGN host sample and control sample. We conclude that the morphologies of X-ray-selected AGN hosts are similar to those of non-active galaxies and most AGN activity is not triggered by a major merger.

  18. X-ray Observations of the Black Hole Transient 4U 1630-47 During 2 Years of X-ray Activity

    NASA Technical Reports Server (NTRS)

    Tomsick, John A.; Corbel, Stephane; Goldwurm, Andrea; Kaaret, Philip

    2005-01-01

    The black hole candidate (BHC) X-ray transient 4U 1630-47 continuously produced strong X-ray emission for more than 2 years during its 2002-2004 outburst, which is one of the brightest and longest outbursts ever seen from this source. We use more than 300 observations made with the Rossi X-Ray Timing Explorer (RM E) to study the source throughout the outburst, along with hard X-ray images from the International Gamma-Ray Astrophysics Laboratory (INTEGRAL), which are critical for interpreting the RXTE data in this crowded field. The source exhibits extreme behaviors, which can be interpreted as an indication that the system luminosity approaches the Eddington limit. For 15 observations, fitting the spectral continuum with a disk-blackbody plus power-law model results in measured inner disk temperatures between 2.7 and 3.8 key and such temperatures are only rivaled by the brightest BHC systems, such as GRS 1915+105 and XTE 51550-564. If the high temperatures are caused by the dominance of electron scattering opacity in the inner regions of the accretion disk, it is theoretically required that the source luminosity be considerably higher than 20% of the Eddington limit. We detect a variety of high-amplitude variability, including hard 10-100 s flares, which peak at levels as much as 2-3 times higher than nonflare levels. This flaring occurs at the highest disk luminosities in a regime in which the source deviates from the L(sub disk) infinity T(sup 4)(sub in) relationship that is seen at lower luminosities, possibly suggesting that we are seeing transitions between a Shakura & Sunyaev disk and a "slim" disk, which is predicted to occur at very high mass accretion rates. The X-ray properties in 2002-2004 are significantly different from those seen during the 1998 outburst, which is the only outburst with detected radio jet emission. Our results support the "jet line" concept recently advanced by Fender and coworkers. Our study allows for a test of the quantitative Mc

  19. X-RAY OBSERVATIONS OF THE BLACK HOLE TRANSIENT 4U 1630-47 DURING 2 YEARS OF X-RAY ACTIVITY

    NASA Technical Reports Server (NTRS)

    Tomsick, John A.; Corbel, Stephane; Goldwurm, Andrea; Kaaret, Philip

    2005-01-01

    The black hole candidate (BHC) X-ray transient 4U 1630-47 continuously produced strong X-ray emission for more than 2 years during its 2002-2004 outburst, which is one of the brightest and longest outbursts ever seen from this source. We use more than 300 observations made with the Rossi X-Ray Timing Explorer (RXTE) to study the source throughout the outburst, along with hard X-ray images from the International Gamma-Ray Astrophysics Laboratory (INTEGRAL), which are critical for interpreting the RXTE data in this crowded field. The source exhibits extreme behaviors, which can be interpreted as an indication that the system luminosity approaches the Eddington limit. For 15 observations, fitting the spectral continuum with a disk-blackbody plus power-law model results in measured inner disk temperatures between 2.7 and 3.8 keV, and such temperatures are only rivaled by the brightest BHC systems, such as GRS 1915+105 and XTE J1550-564. If the high temperatures are caused by the dominance of electron scattering opacity in the inner regions of the accretion disk, it is theoretically required that the source luminosity be considerably higher than 20% of the Eddington limit. We detect a variety of high-amplitude variability, including hard 10-100 s flares, which peak at levels as much as 2-3 times higher than nonflare levels. The X-ray properties in 2002-2004 are significantly different from those seen during the 1998 outburst, which is the only outburst with detected radio jet emission. Our results support the "jet line" concept recently advanced by Fender and coworkers. Our study allows for a test of the quantitative McClintock & Remillard spectral state definitions, and we find that these definitions alone do not provide a complete description of the outburst. Finally, for several of the observations, the high-energy emission is dominated by the nearby sources IGR J16320-4751 and IGR J16358-4726, and we provide information on when these sources were bright and on the

  20. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

    Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

    1990-01-01

    The annual progress report on Cosmic X Ray Physics is presented. Topics studied include: the soft x ray background, proportional counter and filter calibrations, the new sounding rocket payload: X Ray Calorimeter, and theoretical studies.

  1. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

    Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

    1991-01-01

    The annual progress report on Cosmic X Ray Physics for the period 1 Jan. to 31 Dec. 1990 is presented. Topics studied include: soft x ray background, new sounding rocket payload: x ray calorimeter, and theoretical studies.

  2. Chest X-Ray

    MedlinePlus

    ... by Image/Video Gallery Your radiologist explains chest x-ray. Transcript Welcome to Radiology Info dot org! Hello, ... you about chest radiography also known as chest x-rays. Chest x-rays are the most commonly performed ...

  3. Joint x-ray

    MedlinePlus

    X-ray - joint; Arthrography; Arthrogram ... x-ray technologist will help you position the joint to be x-rayed on the table. Once in place, pictures are taken. The joint may be moved into other positions for more ...

  4. Cross-relaxation quenching of x-ray excited luminescence in Eu-activated phosphors

    NASA Astrophysics Data System (ADS)

    Pacold, Joseph; Mortensen, Devon; Reichlin, William; Finfrock, Zou; Diaz, Anthony; Seidler, Gerald

    2015-03-01

    Compounds, molecules, and nanoparticles containing lanthanides as primary constituents or as dopants are widely used in applications including luminescent dyes and lighting phosphors. Recent work has shown that x-ray spectroscopy methods can be used to monitor the sequence of excited states that leads to luminescence in lanthanide materials. Here, we use x-ray excited optical luminescence (XEOL) to identify a nonradiative process that quenches the emissive excited state of Eu3+ in the phosphors YVO4:Eu3+ and YVO4:Bi3+,Eu3+. Taking advantage of the high flux (up to 2 ×1012 photons/second) and focusing capability (beam FWHM 5 μm) of a modern synchrotron beamline, we observe saturation of the XEOL yield at high x-ray flux densities. The saturation effect is interpreted with a kinetic model in which pairs of excited Eu ions undergo an Auger-like cross-relaxation. This effect is well documented in the literature on cathode-ray phosphors, and allows us to estimate the excited fraction of Eu3+ ions. We discuss applications of this method to the broader problem of studying energy transfer in luminescent materials, as well as technical implications for future x-ray spectroscopy studies that require high flux.

  5. 38 CFR 3.370 - Pulmonary tuberculosis shown by X-ray in active service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Pulmonary tuberculosis... Rating Considerations Relative to Specific Diseases § 3.370 Pulmonary tuberculosis shown by X-ray in... connection for pulmonary tuberculosis. When under consideration, all available service department films...

  6. 38 CFR 3.370 - Pulmonary tuberculosis shown by X-ray in active service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... connection for pulmonary tuberculosis. When under consideration, all available service department films and subsequent films will be secured and read by specialists at designated stations who should have a current examination report and X-ray. Resulting interpretations of service films will be accorded the...

  7. 38 CFR 3.370 - Pulmonary tuberculosis shown by X-ray in active service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... connection for pulmonary tuberculosis. When under consideration, all available service department films and subsequent films will be secured and read by specialists at designated stations who should have a current examination report and X-ray. Resulting interpretations of service films will be accorded the...

  8. 38 CFR 3.370 - Pulmonary tuberculosis shown by X-ray in active service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... connection for pulmonary tuberculosis. When under consideration, all available service department films and subsequent films will be secured and read by specialists at designated stations who should have a current examination report and X-ray. Resulting interpretations of service films will be accorded the...

  9. 38 CFR 3.370 - Pulmonary tuberculosis shown by X-ray in active service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... connection for pulmonary tuberculosis. When under consideration, all available service department films and subsequent films will be secured and read by specialists at designated stations who should have a current examination report and X-ray. Resulting interpretations of service films will be accorded the...

  10. High Resolution X-ray Imaging

    NASA Technical Reports Server (NTRS)

    Cash, Webster

    2002-01-01

    NAG5-5020 covered a period of 7.5 years during which a great deal of progress was made in x-ray optical techniques under this grant. We survived peer review numerous times during the effort to keep the grant going. In 1994, when the grant started we were actively pursuing the application of spherical mirrors to improving x-ray telescopes. We had found that x-ray detectors were becoming rapidly more sophisticated and affordable, but that x-ray telescopes were only being improved through the intense application of money within the AXAF program. Clearly new techniques for the future were needed. We were successful in developing and testing at the HELSTF facility in New Mexico a four reflection coma-corrected telescope made from spheres. We were able to demonstrate 0.3 arcsecond resolution, almost to the diffraction limit of the system. The community as a whole was, at that time, not particularly interested in looking past AXAF (Chandra) and the effort needed to evolve. Since we had reached the diffraction limit using non-Wolter optics we then decided to see if we could build an x-ray interferometer in the laboratory. In the lab the potential for improved resolution was substantial. If synthetic aperture telescopes could be built in space, then orders of magnitude improvement would become feasible. In 1998 NASA, under the direction of Dr Nick White of Goddard, started a study to assess the potential and feasibility of x-ray interferometry in space. My work became of central interest to the committee because it indicated that such was possible. In early 1999 we had the breakthrough that allowed us build a practical interferometer. By using flats and hooking up with the Marshall Space Flight Center facilities we were able to demonstrate fringes at 1.25keV on a one millimeter baseline. This actual laboratory demonstration provided the solid proof of concept that NASA needed. As the year progressed the future of x-ray astronomy jelled around the Maxim program. Maxim is a

  11. Synthesis, X-ray crystal structures and catecholase activity investigation of new chalcone ligands

    NASA Astrophysics Data System (ADS)

    Thabti, Salima; Djedouani, Amel; Rahmouni, Samra; Touzani, Rachid; Bendaas, Abderrahmen; Mousser, Hénia; Mousser, Abdelhamid

    2015-12-01

    The reaction of dehydroacetic acid DHA carboxaldehyde and RCHO derivatives (R = quinoleine-8-; indole-3-; pyrrol-2- and 4-(dimethylamino)phenyl - afforded four new chalcone ligands (4-hydroxy-6-methyl-3-[(2E)-3-quinolin-8-ylprop-2-enoyl]-2H-pyran-2-one) L1, (4-hydroxy-3-[(2E)-3-(1H-indol-3-yl)prop-2-enoyl]-6-methyl-2H-pyran-2-one) L2, (4-hydroxy-6-methyl-3-[(2E)-3-(1H-pyrrol-2-yl)prop-2-enoyl]-2H-pyran-2-one) L3, and (3-{(2E)-3-[4-(dimethylamino)phenyl]prop-2-enoyl}-4-hydroxy-6-methyl-2H-pyran-2-one) L4. L3 and L4 were characterized by X-ray crystallography. Molecules crystallize with four and two molecules in the asymmetric unit, respectively and adopt an E conformation about the Cdbnd C bond. Both structures are stabilized by an extended network O-H … O. Furthermore, N-H … O and C-H … O hydrogen bonds are observed in L3 and L4 structures, respectively. The in situ generated copper (II) complexes of the four compounds L1, L2, L3 and L4 were examined for their catalytic activities and were found to catalyze the oxidation reaction of catechol to o-quinone under atmospheric dioxygen. The rates of this oxidation depend on three parameters: ligand, ion salts and solvent nature and the combination L2[Cu (CH3COO)2] leads to the faster catalytic process.

  12. MEASURING X-RAY VARIABILITY IN FAINT/SPARSELY SAMPLED ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Allevato, V.; Paolillo, M.; Papadakis, I.; Pinto, C.

    2013-07-01

    We study the statistical properties of the normalized excess variance of variability process characterized by a ''red-noise'' power spectral density (PSD), as in the case of active galactic nuclei (AGNs). We perform Monte Carlo simulations of light curves, assuming both a continuous and a sparse sampling pattern and various signal-to-noise ratios (S/Ns). We show that the normalized excess variance is a biased estimate of the variance even in the case of continuously sampled light curves. The bias depends on the PSD slope and on the sampling pattern, but not on the S/N. We provide a simple formula to account for the bias, which yields unbiased estimates with an accuracy better than 15%. We show that the normalized excess variance estimates based on single light curves (especially for sparse sampling and S/N < 3) are highly uncertain (even if corrected for bias) and we propose instead the use of an ''ensemble estimate'', based on multiple light curves of the same object, or on the use of light curves of many objects. These estimates have symmetric distributions, known errors, and can also be corrected for biases. We use our results to estimate the ability to measure the intrinsic source variability in current data, and show that they could also be useful in the planning of the observing strategy of future surveys such as those provided by X-ray missions studying distant and/or faint AGN populations and, more in general, in the estimation of the variability amplitude of sources that will result from future surveys such as Pan-STARRS and LSST.

  13. Solar Hard X-ray Observations with NuSTAR

    NASA Astrophysics Data System (ADS)

    Marsh, Andrew; Smith, D. M.; Krucker, S.; Hudson, H. S.; Hurford, G. J.; White, S. M.; Mewaldt, R. A.; Harrison, F. A.; Grefenstette, B. W.; Stern, D.

    2012-05-01

    High-sensitivity imaging of coronal hard X-rays allows detection of freshly accelerated nonthermal electrons at the acceleration site. A few such observations have been made with Yohkoh and RHESSI, but a leap in sensitivity could help pin down the time, place, and manner of reconnection. Around the time of this meeting, the Nuclear Spectroscopic Telescope ARray (NuSTAR), a NASA Small Explorer for high energy astrophysics that uses grazing-incidence optics to focus X-rays up to 80 keV, will be launched. Three weeks will be dedicated to solar observing during the baseline two-year mission. NuSTAR will be 200 times more sensitive than RHESSI in the hard X-ray band. This will allow the following new observations, among others: 1) Extrapolation of the micro/nanoflare distribution by two orders of magnitude down in flux; 2) Search for hard X-rays from network nanoflares (soft X-ray bright points) and evaluation of their role in coronal heating; 3) Discovery of hard X-ray bremsstrahlung from the electron beams driving type III radio bursts, and measurement of their electron spectrum; 4) Hard X-ray studies of polar soft X-ray jets and impulsive solar energetic particle events at the edge of coronal holes; 5) Study of coronal bremsstrahlung from particles accelerated by coronal mass ejections as they are first launched; 6) Study of particles at the coronal reconnection site when flare footpoints and loops are occulted; 7) Search for weak high-temperature coronal plasmas in active regions that are not flaring; and 8) Search for hypothetical axion particles created in the solar core via the hard X-ray signal from their conversion to X-rays in the coronal magnetic field. NuSTAR will also serve as a pathfinder for a future dedicated space mission with enhanced capabilities, such as a satellite version of the FOXSI sounding rocket.

  14. X-RAY FLUORESCENCE ANALYSIS OF HANFORD LOW ACTIVITY WASTE SIMULANTS

    SciTech Connect

    Jurgensen, A; David Missimer, D; Ronny Rutherford, R

    2006-05-08

    Savannah River National Laboratory (SRNL) was requested to develop an x-ray fluorescence (XRF) spectrometry method for elemental characterization of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) pretreated low activity waste (LAW) stream to the LAW Vitrification Plant. The WTP is evaluating the potential for using XRF as a rapid turnaround technique to support LAW product compliance and glass former batching. The overall objective of this task was to develop XRF analytical methods that provide the rapid turnaround time (<8 hours) requested by the WTP, while providing sufficient accuracy and precision to determine waste composition variations. For Phase 1a, SRNL (1) evaluated, selected, and procured an XRF instrument for WTP installation, (2) investigated three XRF sample methods for preparing the LAW sub-sample for XRF analysis, and (3) initiated scoping studies on AN-105 (Envelope A) simulant to determine the instrument's capability, limitations, and optimum operating parameters. After preliminary method development on simulants and the completion of Phase 1a activities, SRNL received approval from WTP to begin Phase 1b activities with the objective of optimizing the XRF methodology. Three XRF sample methods used for preparing the LAW sub-sample for XRF analysis were studied: direct liquid analysis, dried spot, and fused glass. The direct liquid method was selected because its major advantage is that the LAW can be analyzed directly without any sample alteration that could bias the method accuracy. It also is the fastest preparation technique--a typical XRF measurement could be completed in < 1hr after sample delivery. Except for sodium, the method detection limits (MDLs) for the most important analytes in solution, the hold point elements, were achieved by this method. The XRF detection limits are generally adequate for glass former batching and product composition reporting, but may be inadequate for some species (Hg, Cd, and Ba) important to

  15. The NuSTAR Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-Ray Background

    NASA Astrophysics Data System (ADS)

    Harrison, F. A.; Aird, J.; Civano, F.; Lansbury, G.; Mullaney, J. R.; Ballantyne, D. R.; Alexander, D. M.; Stern, D.; Ajello, M.; Barret, D.; Bauer, F. E.; Baloković, M.; Brandt, W. N.; Brightman, M.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W.; Del Moro, A.; Forster, K.; Gandhi, P.; Giommi, P.; Grefenstette, B. W.; Hailey, C. J.; Hickox, R. C.; Hornstrup, A.; Kitaguchi, T.; Koglin, J.; Luo, B.; Madsen, K. K.; Mao, P. H.; Miyasaka, H.; Mori, K.; Perri, M.; Pivovaroff, M.; Puccetti, S.; Rana, V.; Treister, E.; Walton, D.; Westergaard, N. J.; Wik, D.; Zappacosta, L.; Zhang, W. W.; Zoglauer, A.

    2016-11-01

    We present the 3-8 keV and 8-24 keV number counts of active galactic nuclei (AGNs) identified in the Nuclear Spectroscopic Telescope Array (NuSTAR) extragalactic surveys. NuSTAR has now resolved 33%-39% of the X-ray background in the 8-24 keV band, directly identifying AGNs with obscuring columns up to ˜ {10}25 {{cm}}-2. In the softer 3-8 keV band the number counts are in general agreement with those measured by XMM-Newton and Chandra over the flux range 5× {10}-15 ≲ S(3-8 keV)/{erg} {{{s}}}-1 {{cm}}-2 ≲ {10}-12 probed by NuSTAR. In the hard 8-24 keV band NuSTAR probes fluxes over the range 2× {10}-14 ≲ S(8-24 keV)/{erg} {{{s}}}-1 {{cm}}-2 ≲ {10}-12, a factor ˜100 fainter than previous measurements. The 8-24 keV number counts match predictions from AGN population synthesis models, directly confirming the existence of a population of obscured and/or hard X-ray sources inferred from the shape of the integrated cosmic X-ray background. The measured NuSTAR counts lie significantly above simple extrapolation with a Euclidian slope to low flux of the Swift/BAT 15-55 keV number counts measured at higher fluxes (S(15-55 keV) ≳ 10-11 {erg} {{{s}}}-1 {{cm}}-2), reflecting the evolution of the AGN population between the Swift/BAT local (z\\lt 0.1) sample and NuSTAR’s z˜ 1 sample. CXB synthesis models, which account for AGN evolution, lie above the Swift/BAT measurements, suggesting that they do not fully capture the evolution of obscured AGNs at low redshifts.

  16. Trends in ultracool dwarf magnetism. II. The inverse correlation between X-ray activity and rotation as evidence for a bimodal dynamo

    SciTech Connect

    Cook, B. A.; Williams, P. K. G.; Berger, E.

    2014-04-10

    Observations of magnetic activity indicators in solar-type stars exhibit a relationship with rotation with an increase until a 'saturation' level and a moderate decrease in activity in the very fastest rotators ('supersaturation'). While X-ray data have suggested that this relationship is strongly violated in ultracool dwarfs (UCDs; spectral type ≳M7), the limited number of X-ray detections has prevented firm conclusions. In this paper, we analyze the X-ray activity-rotation relation in 38 UCDs. Our sample represents the largest catalog of X-ray active UCDs to date, including seven new and four previously unpublished Chandra observations presented in a companion paper. We identify a substantial number of rapidly rotating UCDs with X-ray activity extending two orders of magnitude below the expected saturation level and measure a 'supersaturation'-type anticorrelation between rotation and X-ray activity. The scatter in UCD X-ray activity at a fixed rotation is ∼3 times larger than that in earlier-type stars. We discuss several mechanisms that have been proposed to explain the data, including centrifugal stripping of the corona, and find them to be inconsistent with the observed trends. Instead, we suggest that an additional parameter correlated with both X-ray activity and rotation is responsible for the observed effects. Building on the results of Zeeman-Doppler imaging of UCD magnetic fields and our companion study of radio/X-ray flux ratios, we argue that this parameter is the magnetic field topology, and that the large scatter in UCD X-ray fluxes reflects the presence of two dynamo modes that produce distinct topologies.

  17. Scientific Drivers for X-Ray Polarimetry Observations of Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Beheshtipour, Banafsheh; Krawczynski, Henric

    2017-01-01

    Although photons cannot escape the gravitational field of a black hole, we can observe the emission from matter spiraling into the black hole forming an accretion disk. X-ray observations are particularly suited to explore the inner structure of the accretion flows onto astrophysical stellar mass and supermassive black holes. In this talk, I will present results from general relativistic ray tracing simulations demonstrating the scientific promise of spectropolarimetric observations of AGNs. Combining timing, spectral, and polarimetric information will allow us to reveal the physical properties of accretion disks and their coronas. I will discuss the potential of X-ray observations for distinguishing between different corona models based on simulations of coronas with different physical properties and in the presence of different sources of seed photons including thermal, cyclotron, and synchrotron seed photons.

  18. Imaging Molecular Signatures of Breast Cancer with X-ray-Activated Nanophosphors

    DTIC Science & Technology

    2014-01-01

    and are working on RLI. 15. SUBJECT TERMS BREAST CANCER , IMAGING, MOLECULAR IMAGING, X-RAY, NANOPARTICLES 16. SECURITY CLASSIFICATION OF: 17...it is important to recognize that cancer nanotechnology is a major venture in the National Cancer Institute, and this technique will benefit from...Kortum, “Real-time vital optical imaging of precancer using anti-epidermal growth factor receptor antibodies conjugated to gold nanoparticles ,” Cancer

  19. An Expanding Plasma Model for the X-ray/radio knots in KPC-scale Jets of Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Sahayanathan, S.; Misra, R.; Kembhavi, A. K.; Kaul, C. L.

    2003-03-01

    We model the observed X-ray/radio knots in Active Galactic Nuclei (AGN) as isotropically expanding spherical plasma clouds fed continously by non-thermal electrons. The time-dependent electron distribution and the emitted photon spectrum are computed using the standard kinetic equation considering synchrotron, adiabatic and inverse Compton cooling processes. We use this model to study the knots of 1136 - 135 and 1150 + 497, recenly observed by Chandra. 29

  20. Ligand discrimination of myoglobin in solution: an iron L-edge X-ray absorption study of the active centre.

    PubMed

    Lange, Kathrin M; Golnak, Ronny; Bonhommeau, Sébastien; Aziz, Emad F

    2013-05-14

    Iron L-edge X-ray absorption spectra of the active centre of myoglobin in the met-form, in the reduced form and upon ligation to O2, CO, NO and CN are presented. The strength of ligation with the iron centre is finger-printed through the variation of the L3 : L2 intensity ratio. Charge Transfer Multiplet calculations are performed and give qualitative information about oxidation states as well as charge transfer.